This marks the last appearance of Chuck Cunningham on the show. He only appeared eleven times in the first 27 episodes. After this he never appeared again but he is mentioned.
In later seasons this episode was replayed as a flashback with the Fonz recounting this Christmas when Arnold, then Al, tell the Fonz they have nowhere to go for Christmas. It was the only time Chuck was mentioned after the original airing of this episode.
Contrary to popular belief, this episode did not get excluded from DVD releases. The only thing that happened is that a song got omitted from the soundtrack.
Though the character of Chuck Cunningham only appeared an even dozen times, including on the original pilot, and though he was never mentioned again after the second season, he was played by a total of three different actors.