It hasn't been redefined at all, you just weren't aware of all the intricacies and conflated every possible symptom into one large, uncommon stereotype, while in reality people in the spectrum are more common than you think but show some symptoms more than others and some not at all.

John, 38 yo virgin, spending 50% of his income on Gundam figurines while living with his aging mother and having no IRL friends is supposedly not "autistic enough" for you if he can hold a job, walk and talk normally? What about that one girl you went to high school with who couldn't stop talking about Supernatural and had a full-on meltdown in front of the whole class on more than one occasion, to the point where she had no friends by junior year and got severely depressed?

These characters were seen as "just weird" until actual scientists started figuring out they were autistic, and now they might have a better life with treatment and the necessary disability benefits