How is attempting to install a different browser and then accepting but being annoyed that it won't let you "attempting to mess up company policy" lol, being allowed to install different browsers on your work laptop isn't exactly unheard of.
If they previously told him that everyone has to use edge, sure, but that doesn't seem likely.
My university forced us to switch from Google Workspace to Microsoft 365 and from BigBlueButton to Teams for online classes probably because Microsoft offered them an irresistible deal. It was a really annoying and user-hostile process for everyone.