The difference between Gmail's IMAP setup and this new Outlook IMAP behavior is the same difference between borrowing a friend's car and stealing a friend's car

The difference between Gmail's IMAP setup and this new Outlook IMAP behavior is the same difference between borrowing a friend's car and stealing a friend's car. In both cases, you're driving a car that doesn't belong to you. The difference is whether you have permission to be driving that car. Both Gmail and Outlook are receiving passwords, then using those to perform IMAP requests from their servers. The difference is that Gmail had permission to do so, while Outlook did not.