My response: No. Autism is always a disability. But disability may not be what you think it is.
OK, let me explain.
Why can I categorically say autism is a disability? Because it's right there in the definition of autism. To be diagnosed, autism must cause significant impairment--that is, it must be a disability. It can be a rather mild one or it can be very severe, or it can (usually does, in fact) depend on the situation the person is in.
But if you can be diagnosed with autism, then you have a disability.
(It is possible to be neurologically and/or culturally autistic, but not diagnosably autistic. This group has autistic neurology and/or social style but cannot be diagnosed because they do not have significant impairment. However, this is not the group that NTs or doctors think of when they say "autism".)
It's the disability stereotypes we need to challenge, not the idea that autism is a disability.
Ask yourself this: What ideas do you associate with the statement, "Autism is a disability"? What does it seem that that statement accuses you of?
Then take those ideas, and ask yourself: "Are those ideas actually true about disability?"
For example: Disabled people can be highly skilled or highly intelligent just like non-disabled people can be. We are neither inferior nor should we be objects of pity. We have many talents. We are individuals. We do not necessarily need more outside help than is utilized by the typical person, though those who don't will need something like more effort, different technology, or a different environment. We can work; we can fall in love; we can have kids. We participate in sports and hobbies. Life with a disability is not any better or worse than life without one (and, yes, people with disabilities have been surveyed, and that was the result).
Disability is not always obvious; nor is it usually extreme. Having a disability is actually quite common, and disabled people represent nearly 20% of the population. Disability does not define who you are--though it is often still a large part of your life and, like any experience you have, will affect your personality and your viewpoint.
If you are autistic and you want to declare yourself equal to other human beings, there is no need to say that you are not disabled, because disabled people are not inferior. Perhaps people have been teaching you for a long time that disability is associated with pity, fear, and inferiority, and you can't reconcile that with the idea that you like who you are, autism and all. But instead of rejecting the idea that autism is a disability, why not re-examine what you have been taught about disability? I guarantee you'll find you've been told some pretty big whoppers...