What we are seeing from PS5 trailers, is a full-on ray tracing solution is out of reach for another generation of consoles. The best they can do is to sprinkle some rt effects here and there. We actually know that for a quite long time, and xbox is no exception. Which puts PC RT in a peculiar position. The rt capability of RTX cards ( 2080 and up) will be far superior than console's, yet who's gonna develop a full-on ray tracing engine?
I don't think it would be too different from how things work today. If console games opt for having features enabled but they switch on/off at different thresholds (distance, roughness, etc.), are of lower resolution, only use it in specific circumstances, etc., the hook for PCs would probably be to introduce higher graphical settings over time that remove those constraints, and also do it at higher framerates and/or resolutions.
By late gen there might be a complex AAA game where the console version would utilize it throughout their game's lighting but fall back to rasterization in certain circumstances or run it at a lower quality, but there's an Ultra setting for the excess power of a 5080 or 6080 that only uses full quality ray tracing. Like console games on PCs today it probably wouldn't really result in it looking like an entirely different game, some visual improvements just aren't that noticeable, but it allows it to go beyond "good enough" to a more complete, accurate picture.
There's Minecraft DXR and Quake II so I assume some work is going into creating path-traced videogames that are simpler or older, and there'll probably be a few indie games that try it, but we're probably years away from being at a point where something like a modern, fairly complex Unreal Engine game could be path traced at playable performance.
