Sony can expect future "Microsoft" games stay in PS platform. Microsoft is a SOFTWARE company. Microsoft do not mind they can MAKE $$$$ by selling games (software) on Sony platform. But it will be naive for Sony to expect Microsoft games to be a Sony platform exclusive. "Playstation exclusive" had been the main console war strategy for Sony for decades. The main objective for Microsoft to spend many BILLIONS is to fight against this.
I can see in future that some Microsoft games will have a "time exclusive" on Xbox(/PC) first, like for 3/6/12 months, then available for PS afterwards.
SELLING GAMES (and nowadays digital shit in games) are the "meat" in game console business.
“I am not a Mac user unless under duress.” - John Carmack