I just tried to register a new team and got the message
"User account already exists with that email."
This may seem odd based on the announcement, but yes this is by design, let me explain...
MM will not let you "Register" a new team with an email that's already in the system. We quickly discovered that people who had trouble with their login i.e. lost a password, would often Register a new team for themselves and then wonder where all their teammate were
. This created problems for the team themselves and us here trying to sort out all the extra registrations.
So back to the same password multi email thing. Often what happens is a person with the same email will be added to two separate teams, often they are not the admin but just one of the team members.
The easiest way around this is to use a different email to create your new account (if you don't have one gmail is a good option), once you have the new account created, you can change the email in your new account to match the other one in the system.
Hopefully that will help.