Inside the ‘Abbott Elementary’ and ‘It’s Always Sunny’ Crossover: Easter Eggs, Character Pairings and Unleashing Five Sociopaths on the School

variety.com:

Michael Schneider Variety Editor at Large This week’s “Abbott Elementary” episode is just half of the story. “Volunteers” featured the long-awaited crossover with FX’s long-running “It’s Always Sunny in Philadelphia,” as told from the vantage point of the hit ABC sitcom.

But you’ll have to wait for the upcoming season of “Sunny” to get the Gang’s take. “Scenes that were happening off-screen in our episode are happening on-screen in theirs,” teases “Abbott” exec producer Patrick Schumacker. “Someone should get ahold of both episodes [once they air] and cut them together.

This isn’t quite the perfect comp, but people keep comparing it to ‘Rashomon.’ We’re not getting different truths happening, but their episode does take place essentially in the same time frame.” Schumacker suggests that Hulu should consider pairing both episodes for audiences to view back-to-back once the “Sunny” version (which has also already been filmed) airs sometime this spring.

But in the meantime, we now have a pretty good idea of what the set-up will be in that episode as well: The “It’s Always Sunny” Gang ends up doing community service at Abbott Elementary — and Melissa (Lisa Ann Walter), who has visited Paddy’s Pub before, recognizes them as the criminals they are. “We were like, who from our cast would ever go to Paddy’s?” says exec producer Justin Halpern. “Oh, Melissa could stumble into that place once.