Do those criticisms of Rosetta hold for Rosetta 2?

I assumed the author was talking about the x86 emulator released for the arm migration a few years ago, not the powerpc one.

They do indeed. Rosetta 2 is lightyears beyond Rosetta when it comes to performance and emulation overhead strategies and benefits from hardware support (and having to do less work just because of fewer differences between the host/target architectures) but still fundamentally relies on the emulation the entirety of the stack. There is almost zero information about its internals disclosed, but from what I understand it still revolves around fat binaries - and necessitates that Apple compiles their frameworks against both x86_64 and arm64. Unlike the MS solution, with Rosetta 2 you cannot call a native ARM64 library from an x86_64 binary, you can't port your code over piece-by-piece, and once Apple decides to no longer ship the next version of xxx framework as a fat binary because they don't want to maintain support for two different architectures in their codebase (wholly understandable), you'll (at best) be left with an older version of said framework that hasn't been patched to address the latest bugs, doesn't behave the same way that newer apps linking against the newer version of the framework do, etc.