My guess:
1. Preemptive measure in case they get eps. from other parts of 1988.
2. They know it\'s an episode from 1988, and they know they have episodes from 1988.
My money is on the second option. As random as some of the copyright strikes are (i.e. a 10 minute block of commercials being zapped because one has a copywritten song), copyright is copyright, and this one is pretty valid, regardless of reason.