"retarded" and "dumb" are also clinical terms. They only stopped being clinical terms because people attached connotations.
For what it's worth, if you're arguing that "disorder" should not be used on the basis of precedents like "dumb" and "retarded", the page you cited is an exceptionally poor reference. The quotes appear to be mocking this phenomenon.
In a clinical context, yes. But there are probably close to zero clinicians in this thread.
One problem with the term "disorder" here is that quite often, it's applied to someone who has difficulty thriving under the many accommodations given to neurotypical people. If the autism spectrum was the norm, neurotypicals would have a similar disorder.
> Whether it will continue to be in the future is irrelevant for present conversation.
Not necessarily. It's perfectly possible for society to lead clinicians on issues like this, which is what seems to have happened with words like "society" and "dumb".