We have an existing Office 365 tenant, which we want to migrate to another Office 365 tenant. We currently use the AAD Connect tool to synchronize user accounts from our on-premise AD to Office 365.
I understand it is only possible to configure AAD to point at a single O365 tenant. We are going to use the Quest On-Demand migration tool to do the actual data copy - this can create a set of onmicrosoft usernames in the new tenancy, but obviously they wouldn't be AAD synced.
Is the only option we have to create the new onmicrosoft accounts, migrate the data and domain, then enable AAD connect against the new tenant? Is there any better option to reduce the risk of email loss during the switch over?
Yes, you would need to stop AAD Connect on the existing tenant and then enable it on the new tenant hard matching the users. AFAIK, there is no proprietary or third party tool which will automate this element.