I'd say it's more about youth than autism. plenty of non autistic young people are into anime too. and as you get older, even with autism, you grow out of it somewhat. I haven't been that into anime in years. only current anime I have any interest in or even pay attention to is Dragon Ball Super. I really think it's an age thing. Almost every person I used to know as a youth that was super into anime, has either stopped watching it altogether now or at a reduced rate.