If you haven’t yet rolled out Edge 16 to your users, I would strongly advise against it. Once the update is installed, users with an MS Entra ID cannot opt out of the new Edge for Business Browser. There are several features that are still unavailable, and currently, there doesn’t seem to be a method to prevent users from establishing a Personal Profile that falls under your established Group Policies. To make matters worse, it appears there’s no straightforward way to halt the use or creation of personal IDs (Refer to the comments in this link: Microsoft Edge for Business FAQ – Microsoft Community Hub).