After removing SfB on prem some users still show as AccountType - SfbOnPremUser

We recently moved to Teams Only and removed all of our SfB on prem servers.  However, while attempting to use the Set-CsPhoneNumberAssignment on a user I got the following error message.

"The user is hosted in an on-premises deployment of Skype for Business Server. This user's number must be changed in the on-premises environment and then synchronized to the cloud."

It seems a few other users are in this state where Teams thinks they are still SfB on prem users.  

Is there a way to stamp the on prem AD account with the correct properties so Teams know they are Teams users?  I don't have an on prem SfB server to move them to Teams.  For example, could I modify one or more of the msRTCSIP attributes on the account?

We use Azure AD Connect to sync our users and are using Direct Routing.