Long ago, sample pages for the Sesame Street 40th anniversary book were posted online, and by the time the book was released a number of changes had occurred. One thing that appeared in the sample pages but not the final released version was a section on Jim Henson's last day on the Sesame Street set, which said that his last segments were Kermit's "I Wonder About the World Above Up There", Ernie's "Don't Throw That Trash on the Ground", and Sesame Street News: The Bird Family. And I noticed all three of those segments used park sets.
I wish that the 40th anniversary DVD included some of Jim Henson's season 21 segments, whether they were from his last day or not. Too bad no such segments were included.