Bart Simpson and Nancy Cartwright visit the Empire State Building to celebrate the 30th anniversary of “The Simpsons” on December 17, 2018 in New York City. Getty Images.

The Simpsons are going full-on throwback this week, from casting Ned Flanders as the coke-dealer-of-the-week on Miami Vice in the opening LA-Z Rider Couch Gag to Bart’s milk mustache. One back ...