"Thanksgiving Reunion" marked the final episode where the original ensemble from "All in the Family" - Carroll O'Connor, Jean Stapleton, Rob Reiner and Sally Struthers - appeared together.
This episode marked Rob Reiner's first (and final) appearance in the series, since season 9 of "All In The Family". Off-screen, the character of Michael 'Meathead' Stivic would divorce Gloria during season 3 of "Archie Bunker's Place" and run off to a commune.
Rob Reiner was offered a returning role for season 3, but turned it down (while pursuing a Hollywood film director career, which became successful).
This was the second half of what originally was a one-hour episode. In syndication and on DVD releases, this was a two-part episode.