This is based on strings discovered in the beta of macOS 11.3 which mentions that installing the update could remove Rosetta 2 from the computer. Another string gives the error message saying that Rosetta is no longer available in this region, and that apps that require Rosetta will no longer be able to run.
Apple is removing Rosetta from Macs during updates in certain countries in Mac 11.3 beta 3. Maybe this is due to legal issues? “Rosetta will be removed upon installing this update” “Rosetta is no longer available in your region. Applications requiring Rosetta will no longer urn” pic.twitter.com/NmsjXOwPvP
— Steve Moser (@SteveMoser) March 3, 2021
This does not appear to be a bug but rather a purposeful action by Apple. It is unclear why they might remove Rosetta 2 from M1 Macs, especially since it’s kind of crucial as there aren’t that many native apps for M1 computers yet. However, as MacRumors speculates, it could be due to legal issues, such as copyright, which could prevent Rosetta 2 from being used in certain regions, which at the moment are unspecified.
This would be rather annoying but the only workaround right now is that users will have to skip the macOS 11.3 update if they want to keep Rosetta, at least until Apple figures this out.