The most charitable explanation I could come up with for this is that many Microsoft-owned 1st party code paths try to change the default browser to Edge, and M

The most charitable explanation I could come up with for this is that many Microsoft-owned 1st party code paths try to change the default browser to Edge, and Microsoft can’t find them all. So instead for compliance the compliance team makes it so all the existing Microsoft code to edit the setting doesn’t work any more and only the code owned by compliance team can edit the setting. This has the “unfortunate” side effect of also breaking 3rd party code that edits the setting.