Over 600 Xbox and Xbox 360 games were already playable on Xbox One. These 600 titles and all Xbox One games will be compatible with the Xbox Series S and X, but that doesn’t mean Microsoft plans to stop there. This is indeed what we read in an interview with Jason Ronald to Game Informer :
“You should never say never. But some games were designed before you thought about intergenerational compatibility. So they present a relatively complex technical challenge. In other cases, it can be a licensing issue. We’re working on this, but it’s hard to go too far here. In any case, we’re thinking about it. ”
Retro titles will automatically benefit from graphical enhancements once launched on Xbox Series S / X, starting with auto-HDR, smoother framerate, and faster load times.