I'll post some Pokémon USUM information. I can't reveal my sources.

-New islands.
-New Tapus: Tapu Gong [Dragon | Fairy type], Tapu La [Fire/Fairy type] (Pokémon Ultra Sun) or Tapu Po [Dark/Fairy type] (Pokémon Ultra Moon) and Tapu Akua [Water/Fairy type].

-Colress go to Alola to try to fuse Solgaleo/Lunala with Necrozma, because of the failure with Black/White Kyurem.

-Like Solgaleo and Lunala, Necrozma has his own "ancient name". It's Kapakila (Armor in Hawaiian)

-New zones in the Ultra Space.

-New 2 UB.

-New legendary Pokémon: _ _ _ _ _ _ _ _

-Gyms are back
Well, I will post more details soon :)