Yes you can on some, Apple's T1 was on x86 to prevent other OSes from installing. ARM isn't as open, RISC-V is, but don't worry x86 will still be staying in the way tha PPC, Amiga, and the ARM based on RISCOS stayed.

>Can you install Windows or Linux on ARM Macs?

ARM Windows sucks. I wouldn't even try, asahi can be installed (but I don't get why you would, all unix stuff works) https://asahilinux.org/about/