The occlusion would need scans form the phone which I can think of one company that can do it fast, then you need to figure out where in the world the user is if you want to occlude using buildings, etc. I know of one company doing that. Neither are working with Microsoft as far as I know.

(I work for the latter company and we do VPS: the thing you'd need to build the game I assume people will glean from the video but they are totally not releasing.)