Outlook 2013: how to reset to “first run” status

TL;DR

Is there a way via script, powershell, reg delete, via telekinesis, whatever to reset Outlook 2013 as if no profiles ever existed and it was running for the first time ever?

Still working through this one but hoping others have insight.

SCENARIO

Lots of users here have existing Outlook profiles connecting to an on-premise Exchange server. We are in the middle of our migration to Office 365. In order to migrate the user's Outlook you have to either create a new profile in Outlook or delete the old profile completely and then "start fresh".

We want our users to start fresh and have the default profile name of "Outlook" for their mail profile (instead of something custom or a 2nd profile like "O365"). This is because our ERP system looks for this profile to send email while in the ERP software.

PROBLEM

The problem is "starting fresh" isn't really starting fresh.

If I manually remove the default profile "Outlook" from the Mail control panel settings, then Outlook starts up without a profile but prompts for a profile name:

If I type Outlook as the new Profile name now I get:

If I go into REGEDIT and look in:

HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem\Profiles

I still see "Outlook" as a profile.

I tried doing a Reg DELETE of this key and all sub-keys and while it says "successfully deleted" it doesn't.

If I manually delete this profile key I can then start Outlook again and when it prompts for a new Profile name I can put in Outlook and it will take it and let me continue as if it is a new setup of Outlook:

It doesn't appear from the command line switches for Outlook 2013 (found here) that the /cleanprofile is still around.

BOTTOM LINE QUESTION

Is there a way via script, powershell, reg delete, via telekinesis, whatever to reset Outlook 2013 as if no profiles ever existed and it was running for the first time ever?