The song everyone sings in the gazebo, "I Will Always Be True," is the same song that was sung in the old Christmas movie Skinner showed during the season 13 episode 'Skinner's Sense of Snow.'
His appearance in this episode's opening couch gag marks "Weird Al" Yankovic's third guest appearance on the show. His first appearance was in season fourteen's 'Three Gays of the Condo' when, at Marge's behest, he performed a parody version of "Jack and Diane" about Homer and Marge. Then, in season nineteen's 'That 90's Show,' Homer became a Kurt Cobain-esque rock star and Al did a parody of his hit song.
Two Star Trek references; Milhouse has always had an Enterprise model in his room, but then Comic Book Guy is given a Vulcan Lyre to play at the protest. The 'Kirk' reference is obvious.
The episode's debate about whether or not to teach certain aspects of history is a thinly veiled reference to the real life argument about Critical Race Theory.
The couch gag features 'Weird Al' Yankovic playing the accordion while the Simpsons dance along. At the end, Weird Al asks if he can stay for dinner but Homer says "No!"