It's not a confirmed PS exclusive at all.
A trailer can be expected imo, but definitely not a 2021 release in any case.
Lol that'd be something else.
last news about the studio
that they were need some support to work in their project
so there is a chance if Microsoft give them the support they will accept it
Ex-Team Ico Developer Fumito Ueda Is Looking for a Publisher for His Next Game
and it will not be strange if Ueda doesn't want work with Sony anymore
i mean he left Sony for reasons