I think that it makes more sense to say that autism may include both disabilities and abilities, instead of saying that it is or isn't a disability.
Myself and my son have aspergers. OK. But in no way is that a disability. An inconvenience in social situations but not in life. So we make our social lives with others who think the same way (OK most are on the spectrum). A bit of training in relationships goes a long way but I wouldn't swap the ability of thinking analytically for anything. It provides much in advantages over normal people in academic settings.
I'm sure a bit of the discrimination we get is based on inability in social situations by normal (whatever that is) people scared by our abilities.