To move a device from one tenant to another:
Note: When a device is moved to a new tenant, the device will be unassigned from its current user and will be unassigned. The device will be removed from any groups of which it is a member. If it is assigned a check-in schedule, this will also be unassigned. Address book entries, event notification rules, geofences and canned messages may also be affected.
It is therefore recommend that this feature is used only when necessary and with caution.