They're fake. The one with the Scorbunny evo by itself shows a Facebook and Twitter username next to the "Confidential" text.
Also, there's this.
Anway, regarding the starters, a Grookey evolving into a gorilla seems a little too obvious. Like, it's seemingly the first thing that comes to people's minds, and almost all fanart I've seen has Grookey going the gorilla route.
Having followed the hype cycles for every generation since Gen IV, I've learned that GF is never that obvious with the starters. What fans want or expect often ends up being completely wrong. GF seems to always find a way to throw a curveball. Like, remember last gen, when most people were expecting Popplio's evolutions to be inspired by clowns? Or the JRPG class inspiration for the Kalos starters, which I don't think was really that evident until their middle stages were revealed? Or Samurott being a thing??
With that being said, we also don't really have enough information on any of these starters to determine anything with any degree of accuracy. We haven't seen them battling or see their moves or really seen anything about them other than that one short trailer.