> If apple uses its own chips, I would assume that they would be aarch64 and not x86_64. Also, Microsoft has some magics for executing x86_64 binaries on aarch64 with good performance, so Apple may have a similar technology.

They definitely do have OSX running on ARM64, they had OSX running on x86 for years before the switch (in fact they had OSX running on x86 before it even was OSX, NeXT ran on x86, SPARC, PA-RISC and 68k, PPC is the one Apple had to add), they've already gone through two architectural migrations (68k -> PPC and PPC -> x86) and by all accounts the iOS core is very much shared with OSX, it wouldn't make sense not to port OSX along the way.