The primary story/explanation of Harry leaving so he can pursue other projects is absolute crap in my opinion. Hank Azaria and Julie Kavner still act in movies, TV and plays while Dan Castellaneta and Nancy Cartright continue to provide voices in other cartoons. I don’t recall Harry’s comedy podcast being suspended before. The point is, money has always been a point of contention and Harry was the most inflexible over it, especially when Fox kept making the empty-pockets gesture despite this cartoon amassing over $2 billion in its lifetime.
Anyway, Harry’s departure is a shame but I say Al Jean and James L. Brooks should use the opportunity to bring the ongoing show to an ending. Wrap up the loose ends, then walk away. Brooks has done it before through The Mary Tyler Moore show.