Are you sure that’s not based on stale information? The M series of laptops by all accounts from the ASAHI developers were written specifically to make it easier to install alternative OSes and ASAHI is no more difficult to install than Linux on a Windows machine.
Asahi Linux is only able to be installed on an M2. They basically take 2 years per new chip, when Apple releases one yearly. At this point, they'll never catch up.
M3 is taking longer than 2 years now. That came out late 2023.