Microsoft
Microsoftbrianchris, since you only added an alias you were still in the mixed MSA and work account state so thank you for confirming the fix. As you noted it would be a good opportunity to disambiguate the two accounts to avoid future disruptions.
jorgecharur, thank you for confirming the fix.
samble, as you noted, Microsoft is optimizing the Office client experience for the cloud first. When the original issue came up about this there was a Uservoice post and you can see the Outlook Team's response on it, https://outlook.uservoice.com/forums/322590-outlook-for-windows-desktop-application/suggestions/36052099-stop-prioritizing-o365-for-autodiscover. The main thing I wanted to point out is that this concern has been raised before and considered. With so much focus on the cloud this is what we have to work with. In any case its good to know the circumstance and try to work with it as best we can. Thank you for taking time to get the traces for us and expediting the investigation.