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).
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 Running an outdated host isn’t the best idea.
Since the hardware will no longer get security updates for the firmware you should stop using it and move to a newer MacBook.
Linux doesn't solve the issue of not getting security updates anymore. For example the FCC does not allow letting users write arbitrary firmware they can run on their devices so this means you legally can't update the Bluetooth or Wifi firmware and need an update from Apple.
The same thing that has previously happened with discontinued Intel Macs or PC hardware that is no longer supported by Windows.
You can still boot Linux natively on it.
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!
Since the hardware will no longer get security updates for the firmware you should stop using it and move to a newer MacBook.
Linux doesn't solve the issue of not getting security updates anymore. For example the FCC does not allow letting users write arbitrary firmware they can run on their devices so this means you legally can't update the Bluetooth or Wifi firmware and need an update from Apple.