users expect support when things don’t work
no shit, that's why you refuse support for users with unsupported configurations.
This is not a new concept.
It's standard for big companies to say they only support RHEL or Ubuntu, in every other case you're on your own.
Instead of axing their entire Linux support they could just do the reasonable thing, which is ignore issues that are out of scope.
Or should they support users trying to run their software on Windows 95, just because it's still technically Windows?
It's compatible just fine. But the quality... well, it's not the worst, but definitely not the best quality.