I recently had a contact in Civi who receives our Constant Contact emails request that we add send messages to her work account instead of her personal account. I proceeded to add her work address to her contact record and mark it as the primary address. CC then marked that contact record (under the original email address) as removed. Because CC keeps track of all contacts by email address, I think the module needs code that will tell CC to create a new contact record under the new Primary Email Address after removing the old, now-not-primary address.