Some short thoughts for the time being, might write more later. Sorry if others have said these already, didn't feel like reading through the whole thread. Also apologies if this is kind of wishlisting, but there isn't a thread for hopes and wishes so eh.
Things I think will happen:
- Move tutors return
- Changed wild Pokemon distribution
- New features
- Most to all features from S/M will be kept, perhaps some will be improved too
- Some kind of new Battle Facility in addition to the Tree being kept
- More content in general, hopefully something like B2/W2 or Platinum but I'm not holding my hopes high for that
- New Z-moves
- New Alola forms (maybe they won't be limited to Kanto Pokemon this time around? One can always dream)
- Some sort of change in the story, Emerald/Platinum-type changes at the very lowest
- New characters, maybe new roles for old characters
- Kind of random, but I expect an animated trailer for the games like the ones for B2/W2 and OR/AS
Things I hope will happen:
- Regional Dex expansion/revamp
- Better training spots. This was my biggest issue with S/M and it needs to be fixed, I hope they'll go back to the epicness of Gen 5/6
- Bring back the National Dex within the game. Not needed, but I want it back, probably my second biggest issue with S/M
- A bigger post-game in terms of area, something like BW/B2W2/DPP/FRLG would be fantastic
- New Mega Evolutions. Unlikely, but I'm a dreamer
Things I don't want to see:
- Pokemon following the trainer. Unpopular opinion, but I strongly disliked this in HG/SS and never want to see it return. I'll be fine if they bring it back and make it optional this time around, but even so, I'd rather see them put effort into actually useful features and not useless gimmicks like this.
- Fan pandering. Specifically, fan pandering to Kanto. The less of it, the better.
More later... if I feel like it.