Question from @mgwilt via Twitter:
I was trying to start from scratch with my Azure AD situation for a proof of concept but it wouldn't let me delete due to a mystery connection. I think that was Office365. So I went to the office 365 admin page and unlinked my domain (A) and deleted everything related. My domain (A) in the azure portal disappeared but I still can't add verify my domain to the new domain because it's still "associated with a tenant", the one I was trying to delete.
Twitter conversation: https://twitter.com/mgwilt/status/687147157711941636
Thanks,
@AzureSupport.