The following games had an update flag but no changelog:

- Beneath a Steel Sky
- Indiana Jones and the Last Crusade
- LOOM
- Magic Carpet Plus
- Pizza Connection
- Sam & Max Hot the Road
- Secret Agent
- Sid Meier's Covert Action
- Syndicate Plus
- Syndicate Wars
- The Dig
- The Feeble Files
- Ultima 8 Gold Edition
- Zak McKraken and the Alien Mindbenders

I can confirm that there were no file changes to the Windows versions of the above games.

Adding Indiana Jones and the Fate of Atlantis to the above list.

Looks like this updates is mac only.

Offline installers are updated now as well.

Populous
Populous 2
Time Commando
got update flags without any changes to their Windows version too, so maybe Mac changes only?

Stardew Valley's Windows version got an update to 1.4.2 as well

Cathedral also got an update. According to the changelog, it's a minor update that fixes a crash in the final battle.

And here's another batch in the same vein:

- Eradicator
- Hocus Pocus
- Personal Nightmare
- Realms of Chaos
- Star Control III
- Waxworks

Better two months late than two decades late.

Project Warlock offline installers are now updated to the current version (1.0.2.1).

Add Terminal Velocity and Screamer 1 & 2

The age of decadence was updated to version 1.6.0.138 (33064)

No changelog available.

The Legend of Heroes: Trails in the Sky SC was updated to version 2019.12.08. No changelog

I am not a Monster: First Contact

Updated to 0.12

And received the Multiplayer Version DLC.

No changelog.

And Wacky Wheels.

Dry Drowning (great game btw) has been updated to ver. 1.05.
No changelog yet but I asked the devs about it on discord and will add this as soon as they reply.