From what I can tell about the Jivey slang, sems they tried to make Baby Rowlf be the surrogate Baby Dr. Teeth.
Anyway, Rowlf's been one of my fave Muppet Babies, and Muppets since the beginning. I wouldn't say he was excluded, since most of the Muppet Merchandise seemed to focus on Kermit, Piggy, and Fozzie (plus Gonzo and Animal), so it would seem that that's the reason why..
I am dissappointed that there may not be any Baby Rowlf stuff, but I have waited my WHOLE life for BAby Scooter/ Skeeter stuff. Unfortunately, Nothing about Baby Bean Bunny or Baby Bunsen and Beaker (Since they have become cult characters, why not have them, too?)
I have yet to see any sort of Quality PVC Muppet Babies at all (that were'nt happy meal premiums). That's what I'm hoping the MB comeback entails...