Many transgender women pre-HRT have very low testosterone levels. It's possible there's some causal arrow between being transgender and having autism, but to be frank much of it could come down to reporting bias, i.e. those with autism are more likely to not care as much about societal expectations and consequently are more likely to embrace being transgender publicly.
This could also be exacerbated by the fact that autism in cisgender women is widely believed to be dramatically underdiagnosed due to gendered societal expectations around behavior and diagnostic tests that only check for traditionally 'male' autistic traits/behaviors.
It's also the case that many individuals transition long after e.g. primary brain development ceases, so it's not particularly likely in my estimation that the body is trying to compensate for past development (given the developmental stage of life is complete).