Not sure I like this. MJ did horrible things, but some of the stuff he admitted himself (eg. the sleeping with kids) has been known for many years now. Just now reacting to a movie's revelations by trying to erase an episode of a show from almost 30 years ago, while I'm pretty sure there have been other cameos by similarly shady people... I don't know, it seems like a weird way to approach it.
Generally not a huge fan of retroactively changing art to fit the modern standards, regulations, court documents, testimonies and whatnot. It's history, they could just slap a banner in front of the episode in reruns saying that they're very sorry about the whole MJ situation but for preservation's sake they will still air the episode as is - in that way they'd show they acknowledged the issues, but they aren't deleting the work of what is also other people (MJ is just one of the hundreds [possibly thousands considering the entire world, the dubs, etc.] of people involved in the creation/distribution/curation of said episode). You can find news pieces from Nazi Germany or Fascist Italy from around WW2. No sane person thinks the content of those were alright, but they are kept around for history's sake, as preservation is important.
I mean, Roman Polanski is a dick, but his movies shouldn't be erased out of existence. Cut him out of the profits if anything, but those movies were worked on by tons of people and are (more often than not) excellent forms of art. OJ is a killer, but that doesn't change what he achieved in sports, they shouldn't erase the results of the teams he played in because of this. Booting Kevin Spacey from an on-going show was the right call given what happened there, but they shouldn't delete his past filmography out of existence because of this, especially in light of the other careers this move would damage. The same scenario applies here: this is a great episode of The Simpsons, one that is memorable and enjoyable for many things. It's not a Michael Jackson one-man show, so keep it. Take the right steps so that MJ (or in this case his legacy) doesn't get money from reruns or reprints, slap a giant banner on it, do whatever you want but why delete art altogether?
Imagine writing a 1200-pages epic book with LOTR-level of detail and planning. You publish it, people love it... but then it turns one of your proofreaders was a pedo, unbeknowst to you, so your book will now never be sold again, people will be unable to enjoy your art again unless they were lucky to buy it in time. I'm not a fan of this kind of approach at all because it ends up tainting art and taking away a creation from other people as well. I understand the reasoning behind it and it's definitely the correct call to disassociate themselves from MJ, but I would have gone about it much differently tbh. Art is a reflection of the times, future events shouldn't change past art, it should just be put in the correct context.