Hi,
I can comment to say that the new Office 365 mailbox option is available in the EAC for Exchange 2016 when in Exchange Hybrid mode with Office 365.
We are considering removing the Exchange Hybrid configuration and did so in our test environment and noticed that the option to create an Office 365 Mailbox was no longer in the EAC for 2016. We are hopeful that we can find a Microsoft supported GUI solution for this if we remove Exchange Hybrid but, it is not looking hopeful at this time.
We are going to continue with an Active Directory hybrid configuration and would like to know if you have any account management/provisioning best practice links you could share after Exchange Hybrid is removed?
Thanks,
Bentley