Depends on the patent. Let's be honest - when has anything patented in the computer/gaming space stopped a tech concept from propagating? You'd think finger-print detection in a phone would be easily patentable and very solid, so only one device (iPhone) would have it for the next 20 years, and yet its ubiquitous.how would devs be able to implement it if it infringes of a patent.
I find it as unlikely that MS has a monopoly on VRS as nVidia has a monopoly on hardware RT acceleration. Just as we all expect AMD to have a RTRT solution, we should expect Sony and everyone else to have VRS somehow.