The exposure to excess iron in infancy increases the amount of dopamine receptors in the brain. https://www.ncbi.nlm.nih.gov/pubmed/18790724 Antipsychotics work primarily by blocking those, without activating them. Autism has been called the opposite of schizophrenia. It has been noticed that when autistic people have high fever or encephalitis, they behave "normally". https://embraceasd.com/the-fever-effect/

I know how it sounds, but that is the best explanation I have.

I find your hypothesis intriguing, but I'm curious about how you would be able to test it and possibly disprove it.

Test if people can actually spot liars (when you know the truth), or if they are not clearly above chance.

Place microphone phased arrays in a loud club, to see if people actually understand each other, or if they hallucinate most of what others say.

Use the same shot of an actor cut in in different contexts, to test if people can accurately see the expression, or if they making it up based on what they know otherwise.

Aside of the obvious of testing the effects of reduced iron intake directly.