Chosen Solution

…….. or should I replace it with new wireless charging coil?

The coil itself consists of a spiral of copper printed onto a sheet of some sort of plastic type material. The copper is the only vital part; it looks to me like the black insulating sheet is what’s torn there, and if that’s the case it should be fine. I do see some copper showing through in the picture, but unless it’s actually damaged, I’d think it would be okay. If it was mine I’d probably go ahead and reassemble the phone, at least far enough to test the wireless charging. If it works, you’re done; button it up and call it good. If not, order a new charging pad and pop it in when it gets there.