They can't stop you from flying over, they can stop you from launching, landing or controlling the drone from their property. If you launch from outside campus - and have VLOS throughout the flight - you're fine.
I’d suggest you search for gimbal repair/replacement on a Mavic 2 pro on YouTube. There are many good instructional videos available. You may find the procedure to reattach your gimbal.
Thus far, my hangar of DJI drones includes two Mavic 2 Pros, a Mavic 2 Zoom, a Mavic Pro Platinum, two Mavic 1 Pros, two DJI Air 1s, a Mini 3, an Air 3, two Phantom 3 Standards, and a Phantom 3 Pro, all bought used on eBay, yet I still track...