Our company is in the beginning process of changing our company name which will affect our Office365 tenant login usernames. For Portal we us single sign on so our current Office365 email login information is used in Portal. Portal is listed in our Active Directory as an Enterprise Application. When I did some testing in changing my user domain name in Office365 login default and tried to log into Portal - Portal created a new user profile for me based on the domain change and in the doing so the new profile is a blank slate (no map, apps, licenses, view only) based on the new domain while keeping my existing account in tack.
How do I avoid the new user profile being created?
Is there a process to follow when changing an email domain name I should be using?