As usual, the patch notes are erroneous in Galaxy. Here are the correct notes for today's patch:

System Shock Demo Patch 1.1 Notes
V1.1
------------------
* The Biological Systems Monitor and Multimedia Reader no longer cast shadows
* Fixed main menu clicks causing player to attack
* Explosion damage has been halved for the demo
* Fixed Hacker throw rotation offset for Proximity Mines
* Fixed issues with loading into an elevator
* Fix for sound on Mobile Laser treads sometimes getting stuck being heard when the Mobile Laser has been destroyed
* EMP Grenade damage fixed
* New attack and improvements to the Mobile Laser
* Physics altered to make some items, including Grenades, less bouncy
* Fixed Cyborg Mantis height so it can fit through certain doors now
* Fixed Broken mix references in main game component
* Destroyable panels are now affected by EMP grenades
* Fixed swapping weapons at the same time as using a power station would prevent the 'use' montage from playing and leave the player permanently unequipped
* Improvements and bug fixes to Saving and Loading
* Under-the-hood changes to Repulsor Lifts
* Explosives can now destroy vending machine screens
* Fixed 1994 mutants falling through the floor
* Simple collision put on the Coins
* End Game Screen issues fixed
* Proximity Mines will no longer hover on Force Bridges and doors when their states are altered
* Sizes of Human Skulls are no longer tiny
* Fixed typos in several places
* Other small minor issues fixed

System Shock (remake) 9th June patch is here.
(Patch note source Steam Community)

- Fixed a crash that could occur when entering Flight Deck with older DX11 versions.
- Fixed a crash that could occur when exiting Maintenance Cyberspace.
- Fixed a crash that could occur when playing Grove Chess.
- Fixed Ragdolls to not fall into place when loading into levels or saves [Players will have to save at least once to see it take effect after downloading this patch]
- Improved grenade rolling behavior when thrown.
- Improved ragdoll behavior on Human Corpse attached to Cortex Reaver.
- Fix for weapons with installed Modkits not always showing their attachments properly.
- Fix Magnum laser sight FX not working properly when loading a save with it enabled.
- Fix elevator music not stopping when the player dies in an elevator and respawns on another level.
- Fix for Audio Log Portrait disappearing in certain cases.
- Fix for game pausing unexpectedly after loading a game.
- Fix equipment soft-lock that could occur when dying while arming an explosive.
- Fix equipment soft-lock when saving and loading while focusing on a puzzle.
- Credit Machines will dispense Tri-Credits when a Finance Chip is used on them.
- Broadcast Monitors can now be shattered when attacked.
- Minipistol Burst-Fire Modkit shoots three rounds instead of two, and can be toggled on/off.
- Bio-Tanks that are destroyed will stop generating hazards after a short duration.
- Items can be bound to the hotbar by pressing a hotbar hotkey while mousing over the item.
- Balance tweaks to Maintenance Cyberspace Level
- Removed duplicate Audio Log from Flight Deck
- Fixed Softlock in Research Level by making Elevator Lobby doors and Circuit Breaker Room door always open if that Quadrant has power disabled.
- Fixed Softlock in Reactor when pulling the Reactor Self-Destruct Lever and reloading a save
- Improved Realspace Enemy AI
- Improved Cyberspace Enemy AI
- Improved Magnum Weapon laser dot FX
- Improved Mag-Pulse Weapon impact vortex FX
- Add Headbob Option to Accessibility Settings
- Added Autosave after using Surgery Machine on every Difficulty
- Fix for Surgery Machine getting stuck in a permanent busy state
- Fix for Energy Shield screen FX not restoring after loading a save
- Fix for pressing Back in the Media Reader to not close entire MFD
- Corrected the Escape Pod Status in MFD Status Screen when triggering Self Destruct sequence

Is this the same as getting "Cannot use while under threat" message while trying to use the machine even though there are no enemies anywhere nearby?

That I couldn't tell you. I've not hit on much in the way of bugs in my play-through, but I've only just reached the reactor level, so I'm far from finished.

I noticed a sudden drop in performance as well as sound stuttering (in a certain area) after the patch was installed.

I'm running the game on 1440p with a Intel Core i5-6600K CPU, 16 GB RAM and a GeForce 1070 with 8 GB VRAM. Not a high-end rig by today's standard. Before the patch however, I had no issues running the game smoothly at 1440p with maxed out settings. Now I have to lower most settings from ultra to high to achieve the same performance.

Also, I've noticed sound stuttering in one area of the game so far: On the Flight Deck every time I enter the office space around Flight Bay 1 the stuttering occurs. When I leave the area it stops. To be fair, I'm not sure if this is actually related to the patch. But I've never noticed any sound stuttering before.

I don't have the patch yet and have observed that same stuttering in the same area (as well as minor stuttering elsewhere), so possibly not related. That Flight Deck office is by the far the worst I've experienced so far.

Okay, thanks for sharing this. I had a hunch this might be the case.

Patch 1.2 changelog:

A female Hacker has now been added as a playable character

Reworked the entire final fight with new mechanics and a unique flow

Cloud Sync support has been added

Other major Changes

Alpha Strain enemies have a new attack
Avian Mutant enemies have a new attack
Cyborg Diego has new movement options
Continued refining enemy AI and behaviors
Mission waypoints have been implemented for (Easy mission difficulty)
Better Gamepad handling and implementation
Major optimizations across the entire game — Steam Deck users rejoice!
Achievements are properly awarded when completing the requirements
Some first person Hacker animations have been corrected
General combat and speed balance adjustments across enemies and weapons
Credits added to the Title Screen
Improved quest logic behavior across several areas of the game
Players can now no longer save over the AutoSave, and the AutoSave will now only appear in the Load Game menu
Game Over screen can now be skipped
Recycle Station ‘inventory’ size has increased to 4x3 from 3x3 to allow recycling of bigger junk items. Scrapper rejoice!
The max payout from a Recycle Station is now 120 Credits
EMP stun duration has been reduced by 25%
SHODAN will lock the Research control room door if the player fires the Mining Laser at Earth
Detox patch now has a 25% protection bonus against environment hazards while active
Fix a soft lock that could occur when dying while interacting with a Surgery Machine
Items dropped inside of elevators should no longer disappear
Pathfinding performance improvements in Flight Deck and Groves
Fix a case where the player was able to clip through the world by loading games while crouched
Fix a case where plasma projectile FX would spawn every frame and wouldn’t clean up properly, causing major frame drops

Minor changes

Easier to see total counts of collected Media items
Added a button to the entrance of the Security level to ensure you can backtrack to the rest of the Station
General FX improvements and tweaks
New artwork on monitors across Citadel Station
Enemy callouts and vocals are less frequent now
Better text sizing for all languages
Jump Jet behavior improved
The color of some projectiles were tweaked
Sped up animations of using Dermal Patches
Enemies who are near Restoration Bays will be teleported to their spawn location to ensure the Hacker doesn’t get softlocked by being killed repeatedly
Save files are now counted incrementally
Fix ups of various Cyberspace levels and enemy placements within
Better handling of Hacker death in unlikely scenarios
SHODAN now has a surprise for the player when Diego is killed on the Security level
Total Enemy Reinforcements have been increased across all levels
Reduced the number of enemies that can bunch up in the same Reinforcement Volume
Enemies will remember the player for longer on all difficulties
Enemy line of checks include the projectile collision radius whenever possible so that their attacks fail less often
Fixed an enemy ambush that wasn’t activating properly in the Medical CPU room if the player comes back later in the game
Kickstarter corpse tokens added to enemies
Enemy awareness in the Flight Deck trap room after saving and loading has been fixed
Diego boss AI adjustments, largely in the first encounter
Cortex Reavers can now perform a strafe jump to more quickly engage the player
Mutated Cyborg and Tiger-Gorilla dismemberment has been fixed
Cyborg Mantis walks faster, will sprint more frequently, and HP increased slightly
Flier-Bots now have an Autocannon in addition to Gas Grenade attacks
Striker-Bots now have a Laser Cannon in addition to Homing Missile attacks
Flier-Bot and Striker-Bot textures have been improved
Fix for Hoppers and Mobile Lasers not being able to hit the player while leaning behind a wall
Security-1 Bot now has a rapid fire attack pose
Cyborg Warrior now has a moving attack similar to the Security-2 Bot
Cyborg Elite Guard head-mounted laser attack damage increased from 60 to 80
Alpha Strain long range attack now has a unique animation
Skorpion default inventory size has been reduced from 4x2 to 3x2
Assault Rifle damage increased slightly from 24 to 25 per round
Plasma Rifle now has an animation to unload the active Plasma Core
Abe Ghiran’s Head inventory size has been increased from 1x1 to 2x2
Missing character portraits have been added
Cyberspace I.C.E Shield FX has been improved
Wire Puzzle has new FX to more clearly indicate the required power level to solve it
Fix for Circuit Puzzle dead-end nodes filling from the wrong side in some cases
Fixed holes in the walls in Research tiles,
Berserk patches now cost 5 Tri-Credits from a dispenser instead of 4
Shotgun ammo cost in Ammo Depots has been reduced from 15 to 14 credits
Loot table adjustments to reduce quantity of ammo received from Exec-Bots, Flier-Bots, Striker-Bots and Cyborg Enforcers
Ammo adjustments in Reactor, Alpha Grove, Delta Grove, Engineering, Security, and Bridge
Reduced the number of First Aid Kit pickups in Flight Deck, Security and Bridge
Assigned the correct idle animation to the Cyborg Drones (No more hovering guns while they are charging)
Jump Jet improvements while in Low Gravity Volumes
Loading a save while falling will properly restore the player’s velocity
Barrel dispensers will no longer drop their dispensed barrels when the player leaves and comes back to a level.
Energy Drain Mines will no longer prepend multiple “Destroyed” strings to their name after being repeatedly destroyed
Fix for player losing Low-Grav/Repulsor mods when switching to certain weapons
Improvements to how the enemy AI handles changing Repulsor Lift direction
Reactor’s Repulsor Lifts have been adjusted slightly to fix potential soft locks
Fix for the player being able to exit the Diego V1 arena by blocking main doorway
Doors will more elegantly restore their collision state when loading a save
Shotgun shell texture has been fixed
Crack-O’s are now no longer considered Junk
Fix for certain wall monitors not breaking when attacked
Fixed small animation issue with the Isolinear Chipset on the Bridge
Fixed sparking cable issues on Maintenance
Fix for several achievements not completing properly
Small text adjustments and spellings
Music playback adjustments
Fixed a potential audio component memory leak when concurrency limits were reached
Added a Controller Vibration accessibility option
Improved gamepad support on MFD
Improved automap performance
Fixed several visual artefacts on the automap
Automap will always update the map info bar with the data for the currently selected level
Implant tooltips will no longer display off the edge of the screen on certain display configs
Fix for the ‘Back’ button on gamepad causing the player to crouch when exiting menus
Credits updated
Other minor improvements, adjustments and balance tweaks