I don't see any patch notes, but the changes are described and illustrated in this article:

https://steamcommunity.com/games/921800/announcements/detail/3033716267134565190

and in this video:

https://www.youtube.com/watch?v=6uQnuLZigv8

See also this video: https://www.youtube.com/watch?v=TNtE4NyKhjE

Hopefully someone on the dev team is watching GOG forums also.

Some feedback on Patch 5. Still have no Blue wing reputation - helped the girl in the warehouse, helped the dude catch a rat and started a truck for one of them (used to give reputation). Blackmailed the head of the blues for 700, would have thought gotten negative rep for that... Have reputation for White, Silver, Black and Orange wings (seem to have almost a fanatical following with the Oranges, even as a Black wing member (75 rep)), and have reputation with Carmine heights, maelstrom, picnic and phalanx - would be nice to see how I'm faring with Blues though.
The servo armor's name is in Russian, till you scan it (both damaged and MK I). Once scanned, the name is correctly in English (since I'm playing in English).
Still have a step in the 'Lights, Camera, Jack!' quest marked as failure (Cheerful Jack, the only survivor died). Not sure how he can be dead, he's drinking up a bunch of booze on level 6 currently and wants to join the team...
Not that I'm complaining, but stealth is way over powered now. I took out the cannibals on stealth and they just ran around wondering who was shooting them. Was pretty amusing. Any harder fight can be fought the same way (start on stealth, blast away till all opposing enemy are dead).
Overall, I'm liking the changes made in the last couple of patch releases and it looks like it will be a great game when finished.

A few more points, I believe I finished all the new content with Patch 5.
The 'We are Family' quest doesn't seem to finish. Rescued the family, sent them to Picnic and visited them there, but no quest completion. Maybe a quest that requires one of the still hidden sites?
There is a 'Tribute to the Memory' quest that may also need access to one of the currently hidden sites. Found 8 bodies and started getting some random encounters that seem related, but nothing has pushed the quest beyond the first initial entry.
When talking to one of the traders that takes Cronos or Founders points, the prompt has a place holder still for both Founder's and Cronos points so you don't know how many you have to trade when trading them in.