That's interesting. In my experience with people on the spectrum, obviously acknowledging that the spectrum is so broad and inclusive at this point as to be almost meaningless in terms of specificity, they really, really, want logical systems and struggle with ambiguity, whether that be in moral, social, or fictional, situations. Clear cut distinctions between wrong and right, and these media properties themselves, give them an almost joyous sense of ease and confidence. It can be very personal for them.

Fantasy and sci-fi themes in media can be complex, but, in my experience, the people I know on the spectrum are far more drawn to fare of a particular kind: systems focused and morally clear-cut. Complexity for them is often more about scale. They'll pick a Brandon Sanderson book/series over a Gene Wolfe book (or Peake's Gormenghast) or a much more thematically and emotionally rich and complicated realist story like Proust's In Search of Lost Time (comparable in a way to the giant fantasy epics with multi volumes). They'll pick an enormous space opera over Ursula K Le Guin's The Dispossessed.

But these are all generalizations. Manifestations of autism can look and be wildly different.