Except the Asahi Linux team are pretty insistent that Apple isn't making it particularly hard. Yes the hardware is novel, but hardly any hardware vendors share low level details on the Intel side either, all that has to be reverse engineered anyway.

Intel themselves writes a ton of the software for their own hardware that makes in into the Linux kernel.

Yeah, they insist on that and then write long blog posts on how they have to reverse engineer basic things which have been contributed by other manufacturers to linux kernel directly.