A bunch of the episodes from The Muppet Show now have a warning in front of them, mostly regarding insensitive portrayals of race, religion and gender. We can argue about whether they are warranted or not, but I think what is more important is the spirit and intent of what they were trying to produce.
But this episode, which doesn't have a disclaimer, is very mean spirited. With characters, primarily Kermit, openly laughing about Miss Piggy's weight (premised on the joke that she is a pig therefore is fat).
What is even more problematic is Kermit is in a relationship with Piggy, and being very disrespectful to Miss Piggy in private and public borders on verbal domestic abuse.
The Muppets are better than punching down at women and overweight people.