Well, you've got to remember that Sesame Workshop was going to produce the Ernie and Bert special, while Disney was going to produce those Muppet productions that got cancled, o the Ernie and Bert special isn't cancled because of Disney (if it has been cancled, then it's for a different reason).
I've also read about a clay animated Ernie and Bert series that was planned. has that show been produced yet?