Create a “Dynamic” AD Group using PowerShell

I had a request come to me today for an AD group that will always contain all of the users in a particular OU.  If you have come across my little place on the internet before, you are likely familiar that I do a lot of work with AD FS.  Keeping that in mind, I wanted to make sure only users that were synced with Azure AD/O365 from this OU were added to the group.  Additionally, if that user were no longer synced with Azure AD/O365 I wanted to remove them from the group to keep it tidy.  And thus I came up with the following script that I have run every hour: