Change O365 group email address using powershell

Just looking a little deeper, using Set-Group doesn't quite get it right when updating the primary SMTP domain. It seems to only update the exchange properties, and not AzureAD.

After using Set-Group, I waited awhile to ensure time for any propagation, and then checked the group objects in both EOL and AAD. While Exchange properties looked good, the AAD properties looked as if nothing had changed.

So, in the office admin portal list and get-msolgroup my test group is still showing the old domain, while the exchange properties and GAL correctly show the new domain. 

Should we expect trouble down the road with a discrepancy like this?

I am also trying to add an email address and then update the new email address to be primarysmtp on a number of old O365 groups.  I can add the new email address just fine, but get the "We failed to update the Unified Group" when I try to set the new address as PrimarySMTP.

Also, not sure if related to this issue, but Set-UnifiedGroup does no appear to be accepting a value for the -HiddenFromExchangeClientsEnabled parameter.  If I try to set the parameter to $true, I get, "A positional parameter cannot be found that accepts argument 'True'."

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From everything I have seen, I should be able to use that parameter so that certain groups will not appear/be discoverable in Outlook and Outlook on web clients.