I think that's fake as well.
Sure it would be cool if Bounsweet evolved into a Grass/Fire, but there aren't any evidences in its design that might point us to that secondary typing.
Although it's Pokémon's 20th anniversary, I don't think GF will put THAT many Kanto caracteristics in the Alola Region. Another thing that sounds really fake is Alola being full of ghost type Pokémon. It just doesn't feel right because, as WingsofBliss said, from the 24 Pokémon we know, only two of them are Ghost- Types. It also doens't seem challenging having a Champion with a full team of ghost types. Sure we had Lance with lots of dragon type Pokémon on its team, but besides that, I don't recall any other champion to have a full team of a specific type. So, I'm guessing that's not going to happen.
About the evil team .. their goal actually reminded me of the video Hikamaru posted, about Sun and Moon being the last Pokémon games (I don't actually believe that). Their goal is to reset the world and start over again, with the right ingredients? (alchemy reference? IDK) , which looks like what that youtuber said: "Pokémon will need a reboot" ... Like, reseting all of this, and start over again. Team Soul also reminded me of Team Galactic, whose goal was to create a whole new world.
About the new day fases, full moon fase would be cool, but what the hell is a full sun? Sounds really fake...
So yeah, I'm 99% sure this is fake xD