Imma take a step back a bit on this. My gut reaction was "GRRRRRRR!", as I'm sure every other Muppet fan's would've been.
But I'm now seeing two factors:
1. All the Muppet performers are probably committed to Sesame this year for the 50th anniversary stuff (the tour, appearances on other shows, possibly the movie as well). So, really not much Disney can do unless they can base a whole series around, I dunno, Yolanda and Mo Frackle.
2. All the stuff they announced today, I'm pretty sure, is all going to be there when the service launches day 1. If there's going to be any new Muppet content, I'd rather it not get lost in the shuffle of other stuff and can properly get promoted.