I suspect as of Big Sur that Apple were intending to release touchscreen Macs, but the changes to the OS in future versions makes me suspect that they then changed their mind.
It's quite possible someone is working on making macOS touch-screen capable, even when they don't have concrete plans for releasing a touch screen Mac.
Lots of hints on touch enabled UI in Big Sur. But whatever it was, seems to have been delayed or suspended.
Not a correction, just adding context: Mac OS X always had Intel builds, even before release. It would be surprising to me if they don’t still maintain Intel macOS builds just in case.
...so I would assume there is plenty of maintenance being done on x86 macOS.
(I confess that personally, after a couple years of trying to make an iPad my main mobile device—and getting pretty good at making it do what I want, learning how capable iPadOS/iOS really is—I’ve retreated to my original circa-2011 understanding of “Macs are computers, iPads are appliances.”)