i have no idea how you think apple silicon will discontinue support for itself.
the hypervisor framework documentation, that i linked above, is pretty clear; the linux builds for arm run extremely fast on apple silicon because hypervisor framework gives them hardware access, in some subsystems directly (memory mapping for example), in other systems through a shim (graphics hardware).
Apple discontinues support for this HW, not Apple discontinues support for running Linux in a hypervisor.
when apple discontinues support for older hardware, it doesn't get OS software updates. that doesn't disable the hardware from running the latest OS before OS updates for the hardware were ended. On the frozen-in-time OS, you'd still have a working instance of apple silicon hypervisor wrapping optimized drivers that make whatever linux arm build you're running still see the hardware.
Some people would like to keep running a system that’s connected to the internet that’s still receiving security updates. Running an outdated host isn’t the best idea.
So you are wrapping Linux in an insecure and never updating wrapper connected to the internet?
Sounds awesome!