I cannot tell you about implementation difference but what I mean is that this only talks about Rosetta 2 for Mac apps. Rosetta for Linux is a feature of the Virtualization framework that’s documented in a completely different place. And this message says a part of Rosetta for macOS will stick around, so I would be surprised if they removed the Linux part.
On the Linux side, Rosetta is an executable that you hook up with binfmt to run AMD64 binaries, like how you might use Wine for windows binaries
Rosetta Linux executable can be used without host hardware/software support; for example, you can run it on AWS's Graviton instances.
However, to get performance benefits, you still need to have hardware support, and have Rosetta installed on macOS [1].
TFA is quite vague about what is being deprecated.
[1] https://developer.apple.com/documentation/virtualization/run...