The news that Abbott Elementary season 4 will feature a crossover with Its Always Sunny In Philadelphia sets up a string of potentially great payoffs shared between the two shows. When Abbott Elementary creator and star Quinta Brunson announced that season 4 of the hit sitcom would include a historical crossover, it seemed like the actor/writer might have been joking or playfully exaggerating. However, the show lived up to this promise with the news that Abbott Elementarys cast of characters will somehow meet the gang from Its Always Sunny In Philadelphia in season 4, despite how unlikely this seems.