I’m a semi-regular DL visitor and I just spent nearly a week in WDW — unless it’s a Marvel, Star Wars, or Pixar property, it’s clearly not getting prioritized. I don’t think Disney is desperate to get Simpsons stuff into their parks. If they were, they could have easily bought Universal out of their contract. The reality is, the current arrangement is mutually beneficial for both parties. Disney doesn’t have to devote resources into incorporating the property, they just earn off the licensing fee; Universal keeps a popular evergreen property. Neither party has to knock down/rebuild anything or reorganize a production budget; they can move forward with the bigger priorities they have.
Unless Disney decides to be jerks about it (which is entirely possible), or if Universal decides they wanna knock it all down and do something brand new, I’d personally bet on Simpsons staying for a good long while.