Jet Set Radio new game was leaked before so the chance of it's being a new game (or remake) is high.
For Sonic ... well it could really just be Olympic games ... or mobile game ... or Olympic Mobile Game.
I wouldn't hold my breath over it. We've had leaks in the past that didn't amount to anything.
As for the Olympic Games, they're subpar, really.
Nintendo Mario Ambassador - Official Update (ft. Shigeru Miyamoto and Charles Martinet)
https://www.youtube.com/watch?v=LbcE4-b0PKs
So Charles Martinet got a big promotion to personally represent and speak for Mario himself outside the games? Is it because of his long term as a voice actor for Mario?
Imagine if Jaleel White or Ryan Drummond stuck around as Sonic's voice. Maybe they would have become Sega Sonic Ambassador.