So overall I have no real issues with moving off of email addresses as a signin name, although it is infinitely easier to keep track, but my main issue is the laziness that this was implemented with. You have obviously been planning this for a while and at the very least should have allowed us to create a new login name at first sign in or change our current display name to something different. This current name dates back to a previous character many games ago that I no longer use nor want to use. This fix needs to be the first thing your "security" team works on after deploying this change so half-assed.