If they have to search your luggage, yes, they will cut your luggage locks off and resecure it with a TSA zip tie. They put a note in your luggage that it was selected for searching.
Sometimes going through the screening process, they can't identify an object in your luggage and they have to search it. That's why they tell you not to put all your books together and to put your shoes on top. some food items also can't be identified.
Coming back last week, my daughters luggage was opened and searched. I saw the blue TSA tag on it when I grabbed it off the belt. We couldn't tell they had even searched it, looked like nothing was moved, they may have noticed her hair dryer, plus she had stashed the cords to the two way radio's and the cell phone chargers in there.
I bought a bag of zip ties (electrical) from Home Depot and threw some extras in the top pocket of my suitcase so we had plenty for the return trip. I believe the stateroom hosts may have some if you need them also.