No, if you are the primary account holder, you will use the same username from before the upgrade. If you have multiple membership numbers now, you will have only one membership number after the upgrade. That number will be the oldest number of any open accounts/memberships at the time of the upgrade. If you use online banking, you will need to log in with the username associated with your oldest membership.
If you are a joint owner, you will need to register for a separate online banking username. Due to increased security requirements, you need to create a username and password that does not match the primary owner’s login details.