I don't think their plan is to make them exclusives. MS makes lots of money from PS (i.e. Minecraft). What I can see is Fallout New Vegas 2, TES6 or any other big game, being free with Game Pass and 70€ for PS5. And you can already see this with The Outer Worlds & Minecraft Dungeons.

That's a power move that wouldn't make half of the consumer base annoyed at you and make everyone want to buy an XSX with the 35€ payment plan. I also hope this pushes Sony to be more competitive with their "exclusive" titles.