I updated to 11.5 today and had an interesting experience.
None of the Intel-only apps that usually launch on login did so, until I launched an Intel-only app manually (by double-clicking on it, not using open
in Terminal) at which point I was prompted to install Rosetta:
I definitely had Rosetta installed before, so I’m not sure why it wasn’t installed after the update.
Once I installed Rosetta, a bunch of Intel-only apps that usually launch on login did so… apparently, they were just waiting for Rosetta… but none of them prompted me for Rosetta.
The same thing happened on my M1 Mac Mini and MacBook Air.
Just something to be aware of!