So, just checked that thread, and no, she did not get attacked because she admitted she had autism, but that she was claiming that it was not a disorder, and the other person just disagreed with her.
https://mangadex.org/title/23112/aspe-chan/comments/
As someone on the spectrum, I can definitely tell you that it fits the definition of a mental disorder, in that it meets the DSM-V's definition of a disorder.
Here's a link that covers the nuances of their operational definitions and its limitations, but Autism Spectrum Disorder definitely falls into the group because it describes a consistent pattern of cognitive and behavioral symptoms that are consistent across a population that can cause distress to themselves or others, and can be caused by underlying biological and psychological phenomena. Not only that but it can cause dysfunction in social situation due to a lack of empathy, a lack of social awareness, sensory issues, etc.
Again, being on the spectrum and having to have special accommodations in my education and having to receive social services I can definitely say that it needs to be classified as a mental disorder. That's not an insult to people who have it, it's the denotative description that allows us to legally receive any aid we need.
PS. For anyone reading, yes I am one of the people she's blocked which is probably ironic given we probably could relate with each in a lot of areas.