If it’s in development it’ll come to PS5 (and maybe even 4 - it’s been so long they probably started there).
1. The project has been costed and built that way - as a multiplat - as far as anyone is aware. Recouping those costs means selling it to the target audiences not suddenly cutting one out. MS is business - they know you spec a project for it’s target sales - they’re not gonna crap on the business planning Zeni have done previously.
2. Some people on that team have spent a significant portion of their careers developing that game for PlayStation (and perhaps other platforms). MS can’t turn up and say “hey thanks for your effort but your last five years get canned and you’re a pawn in our corporate machine now”. Those guys will be out the door day one - MS won’t be trying to piss off anyone.
Whatever is in development will be deployed where it was supposed to go. Even if they do a half assed job just to get it out the door.