We would really like the Global Admins in O365 to have full admin rights over the Microsoft Teams for archiving purposes. Is this ever going to be the case? With hundreds of Teams in a school environment with teachers who come and go, it is an administrative/logistical nightmare to ask teachers to do this.
I dont think so! Administrator have the possibility to administer via teams admin center and also add themselves to the group! In this case you need to script membership of an admin account to be member of all groups / teams