What stage of the roll out are we where I don’t even see 3.7-flash which was released 2-3 weeks ago?

Try updating the app? You should see at least 3.7 I think. It's been available for quite some time.

The app is up to date :)

Well it's in AIStudio and Antigravity always the same day even free tier. Chat is usually low priority, especially if you don't have subscription. Are you on Pro/Ultra?