I did not know this concept existed, Wonderful Idea, no doubt demakes would be a lot more frequent if we valued ecology and actually tried to curb digital obsolescence as much as possible, in a permacomputing way.
I imagine it would be much more straightforward to port pretty much any indie games to consoles like Xbox original onwards, PS3 onwards, Wii onwards, maybe Windows 7 average desktop and notebooks (lots of indies already use older direct x and are compatible with windows 7 , another win for the pc master race). The AAA Games would need to be done with less scale and no 4k dlss ray tracing whatever.