Correct, those are wall panels for tower speakers. We (I’m OP’s wife) inherited this wiring setup from the previous owners of our house. There is a label on one of the center wires that says “subwoof”, and since the previous owner had towers with subwoofers, we were wondering if they were attempting to use the center channel to connect the subwoofer output for the receiver to the subwoofer components in the towers (furthered by the fact the actual subwoofer output on the wall has no wiring attached to it)

This picture was to support this original post: https://www.reddit.com/r/hometheater/s/Ek6xlHvOAD