In general, I'm specifically skeptic of claims of behavioral changes associated with HRT, as I feel as if a lot of those claims have roots in gendered preconceptions of women that have nothing to do with biological differences. People going through HRT will associate personal, unrelated, experiences with the medical transition, but cannot be corroborated through any studies or research.
The most obvious example was my response to emotional situations in fiction. Going from only being able to empathize with characters only on an intellectual level to also being able to empathize on an instinctual/emotional level was was so incredibly obvious it was like going from black and white to color.
One the one hand, you could dismiss "I cry at movies now" as just an intellectually-driven conformity with gender stereotypes. You could dismiss my self-report as rationalization--even a dishonest one. On the other hand, what we're fundamentally talking about here is my own mental states--something about which I have first hand observation and you can have only assumptions.
Go through the thought exercise of what kind of information you'd need to evaluate this kind of claim scientifically. You'll quickly realize how incredibly implausible it would be that anyone would perform (or fund!) a study like this.
Seeing as that's never going to happen, You're left with the choice of either (1) believing people's self-report as the best available evidence, or (2) requiring trans people to solve something like the "Chinese Room Argument" just to justify that their own mental states are, in fact, real. It's like asking someone to prove they actually love their spouse, and aren't just simulating that behavior. Who else is subjected to this level of burden of proof? It's totally unreasonable.
I do understand that these things are different for everyone and it's basically impossible to prove, but you can understand my skepticism. I definitely experienced some of the emotional elements you mention, but they aren't new to me. I don't cry or get upset now where I wouldn't have before. It does feel different though. I do not think this is the same as some of the behavioral changes that the parent is describing. My behavior hasn't changed. I'm still just as much of a nice/mean/thoughtful/forgetful/etc person that I was before. I had ADD before, I have ADD now. My political views haven't changed, I don't treat my friends differently, my hobbies haven't changed. I can't think of anything special about autism that would allow for those symptoms to change because of HRT.
That is, I eventually learned how to process emotions 'correctly', something I was never taught as a child. This is coincident with my transition. I am unclear if it has been directly caused by HRT, but I haven't ruled it out.
However. I absolutely disagree that this is a change caused by "intellectually-driven conformity with gender stereotypes".