As usual, @brinerustle has put things better than I could, but let me give my take as well.
My take is also that it is a “sloppy” use of the term “AI” by AOSP for this new feature (see what I did there? 
) They think they can just add the term “AI” and be all trendy. But I would say that likely a great majority of privacy-focused custom ROM users are triggered by that word in a “not good way” like nails being dragged across a chalk board.
In my understanding and as others have noted, the “group conversation summary” feature is simply one that is adapted based on other inputs, as good software in general should do. Other examples that have been with us for some time that could have been “sloppily” labeled as “AI” features:
- “battery optimization” for an app
- auto-removal of app permissions if you haven’t used the app for some time
- phone not ringing if the caller isn’t in your contact list
Since these “smart features” existed before the “AI craze” they weren’t labeled “AI”, but I would hazard a guess that if they were just introduced they would all have the term “AI” associated with them
Regarding the lack of transparency, yes this is maybe one feature that should have made our 7.3 release announcement which I didn’t make a post about yet as I was away this past weekend, but look for it shortly, and then we can followup up there more broadly on introduced features.
Last note: these major interface updates and new features are more substantial when going from v7.2 to v7.3 than when going from v6 to v7! I find this a bit less than ideal, but it is the way that AOSP development has gone.