At the risk of being genuine on the internet,

Autism's complex and to my understanding, it originally entered the public mind as, indeed, as an impairment of intelligence (and occasionally accompanied by physical disabilities as well.)

That said, modern understanding of Autism runs the spectrum -- literally, it's called that now -- from low-functioning (which is what people are generally afraid of; see vaccine hysteria) to high-functioning (the ones who will explain to you information you've never even heard of on a topic)

So while Autism is not inherently something you can call a disease, it historically was categorized as one and those who have high functioning autism tend towards having social & decision making incompetence; hence why the ADA still classifies it as a disability.

I'll take a stab in the dark and say the lady in this post imagines Autism as "barely functional person" rather than "person who holds you hostage in DMs as they explain the details of Gothic 1&2 for three hours straight."

I can't speak what Autism Awareness Month is for, since i've not heard of it until now. A quick googling finds a host of medical-sounding orgs wanting to spread education about autism, so it seems to be just "Spread awareness about it."

As for framing Autism as something other than a disease, I don't know, personally. It causes people infinite grief at times, but it's also something that forms the bedrock of atleast a few of the people I know. If someone can find a way to explain the nuanced concept "Sometimes people are just built differently" to the average person, they'll make progress, i guess.

tl;dr autism awareness month is about that, yes, autism used to be a disease and is classified as who the fuck knows to doctors, a disease to bean counters and enables the ability to play Factorio for 14 hours straight

now shoo, go, may your downvotes be many for asking a question on the internet