Last I heard, there were graphics driver issues left to iron out.

Linux 5.13 was the first with M1 support. Dunno if that's enough for M1 Pro/Max.

I assume because so far the only devices released with M1 processors have been consumer devices with attached screens, the focus has been on bringing over the full graphical, desktop Linux experience to it, not just headless server linux.

I think you’re forgetting the Mac mini

You're right, I forgot they updated the mini with the M1 last year too.