Allow for change of Profile Email in a single sign-on setup

From time to time, employees of a company change their email address (in our case, we have more than one email domain within the company, which is another reason to change emails).  Currently, if you change email, you cannot update your current profile with the new email and would have to delete old account and create a new account. With that, you will lose all ownership and settings.  Yes, you can update ownership of features, requirements, ideas, to-dos, etc., but it is time consuming.  Why not allow the account administrator to simply change the email of the profile?!