Some Chinese leaked lots of info for this game and all has been legit so far:

https://archive.nyafuu.org/vp/thread/27172920/#27174081

Real leaks;
No gyms
More than 1 evo for Rockruff (including a werewolf)
Yungoos' evolution is fat and hairy.
Time works differently in each version
New forms for old Pokemon (not Megas, think Shellos/Wormadam)
Pokemon transferred from the VC releases will have pre-gen 6 typings/stats.
The stone bracelet has nothing to do with Synchro Evolution.
Ash-Greninja is in the game.
S.S. Anne appears in the game.
Larger, but not by much, amount of brand new Pokemon than last gen.
Looker, Cynthia, Blue, Zinnia, AZ, and Lance all make appearances.
Furfrou's hair cut can be changed in the new Amie.


Some of the new forms for old Pokemon get new animations (Ones I know of include the Abra line)
Transferring through Bank will be the only way to get some forms of old Pokemon.
There is a Flying type bird Pokemon whose appearance varies by island (think Darwin).
There is a 2-stage cat Pokemon that is normal when captured in the wild, but it will inherit the father's primary type as it's 2nd type when hatched; the color/pattern varies by type (think Vivillion).
The Snowman from the Chinese leaks is real; Ice/Ghost. 2-stage.

Butterfree = Bug/Psychic
Rattata line = Dark
Nidoqueen/Nidoking = Poison/Fighting
Ninetales = Fire/Fairy
Growlithe line = Water
Abra line = Fighting
Duduo line = Fighting/Flying


What else is real?