I think obviously it's a two-way street. There are many factors here. They seem to be oversimplifying the issue, which is perhaps understandable but will lead to erroneous conclusions rooted in bad mental models.
My take is that in overall ASD is next evolutionary change in brain development, where things that were coming from natural animal world are given away - that includes easy and intiutive social interaction that monkeys have, filtering of visual and sensory information that is bombarding our brains, where normally humans ignore 80-90% of information that brain receives and that includes gut behaviour as well. Apparently this brain development change can come together only with prolonged life.