apparantly google translate says "for a video i thought i was in fortnite", which makes absolutely no sense.
anyways, he isn't in fortnite, that would be dumb. how would sonic even fit in fortnite anyways?
i think they thought that the blue rings rumor was real.
if you don't know what im talking about, here's an explanation:
Basically in one of the locations, there was a quest where you had to collect 10 blue rings, in which people speculated...
OMG SONIC GONNA BE IN FORTNITE!!!! (i think that this was around the movie's hype so it would make sense for some kids to believe it)
tldr; dont believe anything you see on the internet lol.