I've had no experience with chromebooks but this sounds VERY much like Autopilot on windows/intune or Knox MDM enrollment on samsung android devices. Ring the

I've had no experience with chromebooks but this sounds VERY much like Autopilot on windows/intune or Knox MDM enrollment on samsung android devices. Ring the school again and talk to their IT, prompt their memories with the words MDM enrollment. I bet one of them will have "AHA!" moment.