Rosetta is an emulator (or, I suppose, a series of emulators), i.e. a piece of software that makes a computer pretend to be another kind of computer. This is also a bit of lower level software that makes a (x86_64) computer pretend to be a different kind of computer (aarch64), in this case, by AoT and JIT translation, though that's an implementation detail. What distinction are you trying to make?

Is this not how qemu works? Is rosetta not considered an emulation layer? For all its name suggests otherwise, I would certainly refer to wine as an emulator, and it also uses these techniques.