This works better when it's something that they're not copying and is mostly about the audio, like all of them working to make a music video for a song.
When watching an episode like this you're forced to compare the animation to the show, and the show's art is good enough but not the most amazing, so you're jumping between styles that are either better than it or worse, and it's too jarring. You can't appreciate the simpler styles because they don't feel good enough, and you can't appreciate the better ones because they just conflict with the simpler and the original styles.
That ridiculous jontron animator mashup? That was ok. Episodes from shows redone? Nah. Unless it's a show with such poor animation or such a simple art style that all the animators replacing it are an improvement.