It only makes sense if those games on PC would net Sony more money than not. As platform exclusives effectively define PlayStation, having them on PC too undermines a lot of the PS console value. Hence it's not something you'd choose to do. Death Stranding is third-party so that's up to Kojima. It is worse value for him to make it platform exclusive than cross-platform as he'd sell many less copies, so no wonder it's cross-platform. Almost certainly up front when negotiating, he said he wanted it on PC and if Sony wouldn't let him, he'd just go third-party or something. So Sony agreed as being console exclusive is better for PS than being available on XB1 also.
For MS, console exclusivity is immaterial as they make money through Windows and store and whatnot. They'll happily give up the console space if every console owner ends up gaming on PC and using their services. So for them, it's about Live exclusivity, not Xbox.
The only likelihood of Sony first-party games appearing on PC is if they are real money makers, like massive multiplayer games, where the revenue from having a huge install base outweighs the losses of promoting the PS platform. Don't expect any Sony AAA single-player titles to come to PC as that's taking away people's reason to own and game on PS and losing all those license fees and network sales. Makes zero economic sense to the console business model which is founded on license fees and recurring service fees.