They were released almost 4 years apart. There were plenty of copies available everywhere to reference back when this first happened. I think this is more of the show finding a new audience who now doesn't have access to those recordings. When this originally happened streaming services weren't even really a defacto thing like they are today.

Edit: The original episode is over 25 years old. The first season would have been released on DVD 3 years before the Nibbler reveal. But there were also VHS recordings and DivX/XviD copies available online.