Everybody hung up on typical console warring fail to realize that it has always been about Game Pass and continuous supply of content on it. The more IPs under MS's control, they can better ensure Game Pass will always be getting new content. If Sony is willing, MS wouldn't even think twice about putting Game Pass on PS5. If it was all only about selling Xbox consoles, there wouldn't be PC Game Pass or xCloud for mobiles/tablets and later, directly on TV.
Phil Spencer and MS don't even see Sony as competition anymore. It's not like MS was worried that Sony would acquire Bethesda or Activision/Blizzard (like they have the money to do that lol). Rather have Microsoft acquire the biggest publishers than Amazon, Netflix or Google.