Post hoc ergo propter hoc. I think your logic is backwards. Parent isn't saying the freedom of online technical spaces turns people trans, but that trans people in those spaces are more likely to make themselves obvious because of the freedoms.
There's also high overlaps between trans and non-neurotypical types. I'd suggest there's the same crossover between non-neurotypical and tech circles so makes sense there's a higher instance of trans in tech.
I'd also suggest that on some level coming out as trans is basically hacker mentality. "This hardware/wetware doesn't look/perform correctly. Let me get a soldering iron/rewrite some code/clothing/hormones/surgery and change that."