The only issues you could have with the reluctor rings is possibly through corrosion under them and they could crack, although it is not a common thing. What is more likely is that through corrosion under the rings , the rings can begin to catch on the ABS sensor. An inexpensive fix for this is to remove the ABS sensor from the hub (not always straight forward) and place a washer between the sensor and the hub when refitting to "lift" the sensor away from the ring.
Tony.