Microsoft
The "-Type Shared" can be used on the *-RemoteMailbox just for specific versions of Exchange (Exchange 2013 CU21 or later and Exchange 2016 CU10 or later).
More details on:
https://support.microsoft.com/en-us/help/4133605/cmdlets-to-create-modify-remote-shared-mailbox-in-on-premises-exchange
https://docs.microsoft.com/en-us/powershell/module/exchange/federation-and-hybrid/set-remotemailbox?view=exchange-ps
In case customer's environment is on Exchange 2010, or unsupported versions of Exchange 2013/2016, we recommend what Jeff mentioned in his blog. More details on https://support.microsoft.com/en-us/help/2710029/shared-mailboxes-are-unexpectedly-converted-to-user-mailboxes-after-di, but, in this situation, the steps provided by Jeff are right and enough. Different than the Microsoft official article, Jeff mentioned, as well, to disable the On-Premises AD object's account, as this is now a RemoteSharedMailbox/SharedMailbox, and the AD account of it should not be active, like for the RemoteUserMailbox/UserMailbox object.
