I dunno, this seems kind of junk sciency. There's all kinds of reasons to walk all kinds of ways. Walking on toes, or pointing your feet have almost never been a notable feature of people I know who are clearly on the spectrum. Conversely, the people I know who do have notable gaits all come from something else and none of them (as far as I know) have autism.

Anecdata: My paternal side has some kind of innate preference for walking on your toes. I prefer it, my father's mother was well known to have done it, I have a couple cousins like that. While I can't speak for other family, I did go through a massive battery of aptitude and psych tests when I was young as part of the agonizing initiation into the curse of childhood giftedness. No autism.

I've become very concerned in the last few years how our society produces diagnoses that turn into self-inhibiting labels that restrict personal development. Developing ones-self, as much as you are able, is an ancient and treasured tradition. Modernity seems to be leading us to the reverse and to shackle ourselves with the weight of imposed limitations.