Found out from some Reddit discussions that the developers aim to first upstream everything for M1/M2 to the kernel, and as of
https://asahilinux.org/2025/08/progress-report-6-16/:
> With Linux 6.16, we also hit a pretty cool milestone. In our first progress report, we mentioned that we were carrying over 1200 patches downstream. After doing a little housekeeping on our branch and upstreaming what we have so far, that number is now below 1000 for the first time in many years, meaning we have managed to upstream a little over 20% of our entire patch set in just under five months. If we discount the DCP and GPU/Rust patches from both figures, that proportion jumps to just under half!
So if the discussions are true, it can take years for the developers to finish M1/M2 upstreaming with all the Linux kernel bureaucracy. That is, unless they decide to start working on M3 before finishing the upstreaming