They were. They were canceled. The sunk cost developing the PS5 version of the game isn't that much in the scheme of things. Microsoft isn't counting pennies here. You're talking millions of dollars of wasted development cost for a 7.5 billion dollar purchase. Microsoft doesn't give two s***s about that.
Can't say much more than this...a Bethesda employee was saying there would be a PS5 version as late as March even while insiders with pretty good Xbox track records were saying there wouldn't be. That employee now doesn't believe there will be a PS5 version. Reason why there's confusion on the issue is because anyone with Bethesda contacts was hearing there were no changes with Playstation development...but that all changed once the Bethesda deal finalized.
Microsoft execs are on record that they believe exclusives are important to driving Game Pass subs. It's literally the only thing that matters to investors when it comes to gaming right now. They aren't worried about recouping millions of sunk development cost if it's going to cost them subs to what they believe will be a multi-billion dollar subscription service.
Don't wait. Don't hold your breath. Of course things can change. Playstation could accept Microsoft's offer to put Game Pass on their system. That looks quite unlikely today though who knows what the future holds. Playstation development has stopped on everything they didn't have commitments or contracts for. There is no contract on Starfield guaranteeing a PlayStation release.