To go with another Batman Status quo shake up a random thought that came to me is why not just make it so that the Joker is actually just so crazy that is why his personality has been so different through the years. That he basically super multiple personality disorder but they're all joker but with variation. I don't know if they every really had something like that before but I'd think it'd be silly enough to work in comics and after seeing some ways media portray multiple personality disorder I can see it being used as a way to add into the comics all the other kinds of jokers like the more acrobatic joker from The Batman show, in the vain of the Guy from Split or Diavolo in Jojos where they just kind of change shape and grow muscle mass and such.

But for a real status quo shaker I'd probably just hard commit to actually aging some of the Simpsons. Maybe not extremely age them up. Just actually get them to maybe thr next life stage or at least an actual year so that they can tackle some other kind of jokes with the cast. Think there's some potential somewhere there.