That is marketing terminology (because "emulation is slow"). Full static transpiling is not a solvable problem - you can't actually take an x86 app, run it through some converter, and get an ARM app out. It's just not a thing and it never will be (without cheating and, like, literally embedding an emulator in the app).
Anything less than that is emulation, and requires dynamic elements. All modern emulators use JIT, and caching the result is similar to AoT translation; plus JIT can be faster than AoT sometimes due to being able to take advantage of runtime profiling, and you can never guarantee ~full AoT translation of even binaries without self-modifying code without additional metadata (like a list of all branch destinations), so Rosetta cannot possibly claim it does that with full coverage. On top of that you need to add a level of indirection to all indirect branches, as you cannot statically change all function pointers in data structures (that's an even harder problem). At that point you're adding enough bookkeeping gunk to the translated code that it is no longer a straight translation, like Apple would want you to believe. JIT is binary translation too, so by Apple marketing standards, qemu, Dolphin, and basically every other modern emulator is also "translation". Which is just not useful.
So everyone saying that "Rosetta 2 is AoT translation" as if that means it's fundamentally better/faster than other emulation technologies is just falling to marketing.
Whatever you call it, it's not fundamentally different from any other emulator in a way that puts it in another class of technology. It is not straight converting x86 to ARM. That's just not a thing and it never will be. The end result is that the CPU is going to be executing a series of translated basic blocks interspersed with code added by the translation to glue everything together, which is the same thing every JIT-based emulator does, and will have the same performance characteristics, and the fact that some of that work can be done ahead of time is not a fundamental difference.
If you want to look for reasons why Rosetta 2 is faster than other emulators, look for places where Apple cheated and made their CPUs implement x86 things like its memory consistency model. That can have massive gains. I bet if you port a decent JIT-based emulator to use that feature on M1, and compare it to Rosetta 2 for number crunching inner loops and such, you'll find you can get very similar performance numbers out of it once the JIT cache is warm.
It'll be interesting when people take a deep dive into specific things Rosetta 2 does.