Yeah the older 440T4s and 4T60Es didnt see this near as often and was the clutch end that would get chewed up more. One thing I have noticed on the 65s if that the minivans and 60deg V6 cars go through these shafts more often. Its one of those gray areas but I always felt that those cars cyclined in and out of 4th under load a lot more frequently which is going to hammer on the splines more and cause them to fail sooner. Regardless the newer shafts seem to address the problem and I havent seen one come back nor have I had anyone tell me about one failing.
