Edit: expanding a bit more on the idea. DIYing all the stuff you’d need to avoid plastics is a much bigger identity statement than neurodivergent. Tho saying I’ve been subtly poisoned is far less sexy than saying I’m neurodivergent.
The problem is that when I have conversations with people about soy turning me trans or social media turning me trans they are often trying to use that as a way to deny me any agency over my own life.
We know that a living being is just not only DNA, but also its environment; now on top of that add all the big complexity of human social behaviour and gender into it. I doubt they will find a "cause" to trans-ness.