The article says 1-5% of the ASD cases they looked at were related to the "HARs" (human-accelerated regions). The most important thing to understand about autism is that it isn't a single condition, but an umbrella category with a bunch of conditions grouped into it.

It's a trait (trait cluster, really), analogous to intellectual disability or giftedness, rather than analogous to a condition with a single known cause like trisomy 21. See https://intellectualizing.net/2013/12/17/book-rethinking-aut... and https://intellectualizing.net/2015/06/04/why-it-matters-whet...

Once we understand that autism isn't a single condition, a lot of the ways the public (and researchers) talk about autism turn out to be kinda nonsense.