I´m trying to understand how Outlook determines which "First Run" Dialog it Displays for a user?
There is this new modern Dialog, where you only press connect, or the old known Dialog where you have to click next, next....done.
I added two screenshots for better understanding.
That's part of the new logic built-in in Outlook to detect O365 accounts and make the process simpler... which is also know to cause issues: https://blog.skykick.com/new-microsoft-direct-connect-feature-may-prematurely-connect-outlook-to-off...
Are you getting both on the same computer? The old one should only come up if you set the registry key to not use the new dialog. It might come up if you go through control panel, mail to create the profile instead of just opening outlook.