The ZIF connector next to the camera is actually the proximity sensor connector. The top right antenna assembly is the primary TX/RX antenna for cellular services(connecting to the top right coax connector) and doubles as a proximity sensor(the ZIF connector next to the main camera). The top left antenna(coax connector under the front camera) is for cellular diversity RX and GPS.
The prox sensor is not used for any user activity, it's just for RF compliance. Leaving it damaged does affect you using it in any way. The parts for cellular iPads are hard to source so I would say just leave it there.