I think the whole network is bluffing.
Expressing interest in something and actually doing something are two different things. Sometimes, things out of network control can stunt a project. Look at the Wonder Woman pilot NBC ordered and then dumped. It was terrible (supposedly), and it would have killed them in the ratings and have been a big setback for WB, especially with their DC comics film and TV brand.
A New Muppet special
can be ordered by CW, but the actual making of the special falls onto Disney. If they can write, film, and edit something by November then this is plausible. If not, the network is only at fault for promising something they can't really deliver on their own, even though most of the problem will lie with Disney if they either pass or deem they can't finish it in time.