If they have to cut off a non-TSA lock, they're supposed to re-secure your bag with cable ties (zip ties).
At MSY, I was asked to help a very friendly TSA guy by providing the key to my bag strap (it's more a shaped tool than a key, really) because he didn't have anything to poke into the slot to turn it. He then cut the cable ties that I use instead of locks whenever flying from a US airport. I then stood and watched him search the bag, which was done well and carefully. He then re-packed everything just as carefully, and then turned to me and asked me if I had any more cable ties - because he hadn't been provided with any.
It was very good of him. And I did have more, which I was able to direct him to. But that goes to show how badly the TSA is run.
So as for expecting your TSA locks to be put back on afterwards? Dream on.