The E-mail just arrived today. That suggests the problem was mostly the bad luck of trying to resolve a FF question in the midst of the change and;
The agents having no idea that changeover was going on at the same time.
Meanwhile the E-mail didn't clarify the log in would be seamless using the same password. I guess the now two identical log-ins to the same FF records is probably temporary
Maybe my post will help others who might get just as "perplexed", to understand