It's an EXPLANATORY theory, guys.

In political science, we talked about normative theories and explanatory theories. The way I see it is this: Normative: A,B,C. Theory Q would explain that. Thus X,Y, Z should be true too, since Theory Q suggests them as well. OR  I think Q is the case. That would suggest X,Y, Z.
Explanatory: Huh. X,Y, Z are true. P would explain those. Looks to see if anything else true would  be explained by P, but doesn't assume that things P could explain are true.
I'm not sure these are exactly right. But they work for making my point. Autism isn't very good at being a normative theory of someones behavior. We vary too much. If you use it as normative, you could assume that ALL autistics do something. Unless that something is ``are autistic," there is probably an exception. We don't all stim. We don't all have eye contact problems. We don't all lack the ability to live alone. We don't all have the ability to live alone. Continue along the same lines. Grab an autistic trait. It might apply to a lot of us, but probably not all of us.
As an explanatory theory, it does a pretty good job. Example: Oh, hey. M won't look anyone in the eye. M flaps his hands when he's happy and rocks when he's stressed. M has trouble making friends. M has some motor control problems. Certain textures drive M completely bonkers. M has a few narrow topics he REALLY likes. Huh. Autism would be a decent explanation for those traits. I'm going to look for more traits of his that autism would explain. You know, that really would explain a lot. I'm not going to assume he has other autistic traits, but yeah, I wouldn't be surprised if M is autistic.
All that is to say, autistic people are the same people they were before you found out they were autistic (unless it's been so long since you found out that natural growing and changing over time messed with that, but I'm really talking about the case where you JUST found out.) If you know one autistic person, you know one autistic person. Autism could totally explain some of that person's traits, but finding out the person is autistic doesn't cause them to suddenly develop more stereotypical autistic traits, make them less intelligent than they were two minutes ago, or anything of the type.