You know, the way "Sesame Street" has changed a lot with the reduced length reminds me of when something similar happened to "Big Bag," another CTW-produced show that aired on Cartoon Network in the 90s (for those who don't remember.)
The first season in 1996 had 13 hour-length episodes, each one comprised of the main story with the human and Muppet cast sandwiched by recurring cartoon segments; these were like 3 to 6-minute cartoon episodes, often coming from different parts of the word, including "Troubles the Cat" (created in the USA for CTW, featuring an orange cat and her "Troublescope" she would use to help figure out problems), "William's Wish Wellingtons" (a BBC import from the UK made by Hibbert-Ralph), "Slim Pig" (another UK BBC series), "Koki" (made in Spain for CTW, basically a claymation "Pingu" knock-off with chickens and ducks), "Tobias Totz and his Lion" (made in Germany) and "Samuel and Nina" (made in Australia by Yoram-Gross, the "Blinky Bill" company). Before the "Koki" cartoon would play, there would be a filmed "Big Bag Beat" music video featuring kids dancing and playing. (I remember one with a song about flying, and it featured kids running around with capes, including a shot that was later reused in the 1998-2001 "Sesame Street" opening!)
In spring 1998, the second season of "Big Bag" debuted, but with a HUGE change. The show was now only a half-hour long, and only would feature three cartoon segments. The only ones from the first season to return were the CTW-made "Troubles the Cat" and "Koki," along with the then-new "Ace and Avery" shorts by John Dilworth. Reruns of first-season episodes were edited down to a half-hour length, cutting a few of the main story segments, and limiting the cartoons. Either a first season rerun would feature a "Troubles" cartoon, a "Big Bag Beat" music video and a "Samuel and Nina" cartoon, or a "Wish Wellingtons" cartoon, a "Slim Pig" cartoon and a "Koki" cartoon. "Tobias Totz" was completely dropped from the show when this happened.
But at least "Big Bag"'s second season brought us the episode where Elmo comes to visit!