Hypothesis: The reason that neurodivergent people (esp. autistic people) tend to lean more trans per capita is because a lot of default gender roles, norms, and assumptions are neurotypical assumed. Thus since there is no pre-packaged "space," ND people have to explore their space in the gender-world "manually."
We're willing to bet that if NT people were in a similar space where they were forced to actively examine their gender and not take anything for granted, we'd see similar rates.
I agree with your conclusion, but I think the causation is (kinda?) the other way around. Under white patriarchy, we're all bombarded with incentives to avoid any such introspection. Those defaults are not inherent or naturally emergent, they're explicitly the things that keep the Right People on top of the power pyramid, and normalcy against those standards is made a valuable goal through visibly punishing anyone who isn't.
So IMO the difference for ND folk is that we're more likely to give up on attempting normalcy for that reason, and thus have less reason to cling to it otherwise since, hey, we're already fucked. Which leads to the same outcome but it's not so much due to lack of introspection among NT folk, as it is lack of jaded resignation causing them to give up on maintaining their denial blinders.