Undoubtedly, it'd take a lot of effort just to get the games to run - but I assume no more effort than it took to get Backward compatibility to work on Xbox, it is the only console that support's it's entire catalog after all... and that's really due to I think rebuilding some of the game's where and when needed if automation cannot handle certain aspect's of design. Just looking at some of the very old Xbox 1 Titles now supported on OneX/SeriesX - some of those asset's have had more polygon's added, look thicker and more robust than before. So some of the game's have improvement's beyond simple resolution boost's with high framerates and less pop in. The original Star Wars Battlefront on Xbox -in backwards compatibility on Xbox One X - the asset's look almost completely different in some cases, as if another level of subdivision has been added or... perhaps even the model's have been reworked/re-topologized. Which is insane to me, and must be a costly thing to undertake.