There’s every chance it will be as good as it was when new, assuming the person who works on it knows exactly what he or she is doing. It most likely won’t be the same as before, but that’s a different matter altogether.
I’ve had a number of cartridges retipped or rebuilt (by Soundsmith, Benz Micro, VdH, Expert Stylus) and every one sounded just as good or better than before. The latest, an AT-OC10, was a particular success and is now about as good as anything I’ve heard after a trip to Soundsmith.
As long as you’re not swapping the boron cantilever and line contact stylus for something inferior you have nothing to worry about.