IDK, MS really went all the way with backwards compatibility. They literally built emulators for the 360 and OG Xbox in order to let people play old games using old disks they already owned.
I'd be shocked if they didn't stay committed to this.
The rumored Series X refresh doesn't have a disk drive.
It'd be hard for Microsoft to remain committed to game preservation in that way without them.
To me, this sounds more like they're looking at Nintendo's virtual store playbook and wondering how many times they can sell the same games to their customer base.