macOS 27.2 stops upgrades from removing Rosetta, Apple's release notes say
Apple has changed how macOS Golden Gate handles Rosetta, the translation layer that lets Intel-based apps run on Apple silicon Macs. According to Apple's enterprise release notes for macOS Golden Gate 27.2, upgrading to macOS 27 no longer removes Rosetta from a Mac where it is already installed.
The note is short. Under the 27.2 section, Apple writes that "Rosetta is no longer removed when upgrading to macOS 27." MacRumors, which spotted the entry, reports that the change is meant to keep existing installations intact during the upgrade.