The Simpsons has plenty of ideas that never made it to fruition, going through the writing process but never seeing the light of day. Sometimes, these unproduced episodes are missed opportunities. In one particular case, it was for the best that the idea never made it across the finish line -- as it would have been a sequel to an episode that's been quietly removed from circulation.
Source：https://www.cbr.com/the-simpsons-stark-raving-dad-sequel/
