I’ve been playing with both the Thumb and the Unexpected keyboards. I like 'em both but, man, I have to admit I’d like them more if they had that top bar that predicts what you might be. Is that just a no-go from a privacy perspective? Can that functionality be local?
(I also wouldn’t mind a good voice typing feature)
While Google isn’t generally good for privacy GBoard actually does this. IIRC they actually completely removed the sync service and your typing history is only kept on-device and Android backup.
However it is a bit of a privacy nightmare otherwise as many of the other features phone home. But last I checked (~4 years ago, worth checking again) the core typing functionality is actually fully offline and private.
So yes, it is possible.