As always, take everything listed below with a grain of salt. I don't work for Game Freak, so I have no idea how true the following information is as it's something I heard through the grapevine by supposed official sources. I'm a little bit dubious about some of the apparent leaks/rumors myself, but here goes:

> 98 brand new 'mons. 5 of which are Legendaries, and there are 2 Mythicals.
> 21 regional variants total from Johto, Hoenn and Kalos.
> Box legendary Pokémon are a wolf and a fox. Dark/Steel and Dark/Electric
> Psychic/Ground third Legendary - last two are Fire/Ice and Grass/Fighting.
> Mythicals are both Normal-types
> 2 Professors: Male named Pine and woman called Cherry.
> 8 gyms total - some are hidden/underground.
> The caves in Kalos and Galar are linked and are accessed half way through the game.

I have more info, so just feel free to ask.