I am super late coming in, but:
When someone first pitched this idea to me, I was assuming it would be something more like POC or QUILTBAG than CC. A place to discuss the social aspects of disability, rights, the push for equality, ways to cope with existing discrimination, news related to these things, and sometimes AWers coming in to ask questions- all the same stuff I've seen in those two forums. And that's what I'm most interested in seeing.
From a purely personal standpoint I do hope the various forms of non-physiological disabilities would be included, but I can understand if they're not and I won't make an issue of it.
What I mean is, I figure I'm not the only AWer who'd love to see a designated spot for the respectful discussions of sanism/mental health stigma, or of intellectual disabilities and the stigma related to those, or of media portrayals of neurovariance, etc that sometimes take place in other forums here... But I know the prejudices people with physiological disabilities face are different and it's not my place to decide whether all disabilities can be discussed in the same subforum.