I own an xbox (previous generation), and pay for game pass. There hasn't been a game on game pass or that has come to the store (that I am interested in) that doesn't play on the previous generation. I _want_ a new one, but haven't bumped up against anything that I haven't been able to do with my older xbox, so I haven't had anything to look forward to or get access to with the new system.
I also wonder how much their naming scheme hinders their sales. I find it so confusing, and the current and previous generations may as well have the same names as I can't disambiguate them.