“ Ultimately though, if this experience isn't right for you, you can turn off this feature the first time it launches in Microsoft Edge, and then in Outlook settings at any time after that. ”
Having said that, Microsoft seem to be entering another phase of baiting antitrust regulators.
Users don't pay attention to this stuff. And then when you have to go back and switch it to the correct behavior of using the default browser, they've buried the option in Outlook (Options > Advanced > Link Handling).