I think some people are in some real denial about the nature of this deal. The games that have been shown on PS5 (and are obviously timed exclusives) are still gonna be published on the platform. But maybe with the exception of an odd game or two (mostly games like Fallout Shelter), future games will almost certainly not be coming to PlayStation. Microsoft would not pay $7.5 billion just for day one Game Pass deals and the profits they would get from PlayStation releases. This is meant to be a supplement to their other first-party studios.
Games like Starfield and Elder Scrolls 6, where we haven't even seen gameplay? Yeah, I'm confident that they'll be Xbox/PC exclusives. Same with pretty much every future major title that has yet to be announced. All you need to do is look at from the other side. If Sony paid 7.5 bil for Bethesda, would you still expect them to publish future titles on Xbox outside of those already deep in development/near release? Of course not.
Sure, they'd possibly make more money short-term from continuing to release future games on PlayStation. But so could PlayStation by releasing games on the Xbox platform, and obviously they would have no interest in that. The point of the deal is exclusivity to convince you to buy into the Xbox platform, be that a system or even just Game Pass Ultimate to stream the games on your phone or tablet. PlayStation releases does not benefit them in that regard. Short-term profits, sure, but it doesn't help their goal of long-term Game Pass viability.