There's another phenomenon that interacts here - there is an observed higher prevalence of LGBTQ in autism (discussed here https://sparkforautism.org/discover_article/autism-lgbtq-identity/ and various research papers). Niche forums such as Lemmy, Fediverse, even Reddit all feel like they also have a higher autism spectrum prevalence than a general population. So I would guess there's a double whammy on representation happening here - extra representation via safe space and shared interest on LGBTQ, extra representation ij autism spectrum, and an extra overlap between these two populations.