The Last Man Expanding

In the opening scene when the guys are trying to figure out what's changed, Lenny guesses "Did a woman named Diane used to work at this bar, and now she's been replaced by a woman named Rebecca?". He's describing Cheers (1982) where this happened, where Diane then Rebecca were played by Shelley Long and Kirstie Alley, respectively. Carl and Homer even go on to talk about Long's departure from the show and the type of character she was.