Devon is full of shit. By extension, Staph is full of shit.
1) An autism diagnosis, when it is correct, can absolutely "unlock access to beneficial treatment." That is actually the whole point of getting a diagnosis. Being diagnosed as autistic (even high-functioning!) can mean someone will learn how to make friends, how to manage sensory overload and be able to go into public places, and they can have access to accommodations at work and/or school that could potentially mean the difference between having gainful employment or being stuck on disability.
2) If you are competent enough to choose whether or not to pursue an autism diagnosis, you are probably also competent enough to get approval for hormones or surgery. If you are not getting approved, it might actually have nothing to do with being autistic.
3) If you are competent enough to choose to not get diagnosed, you are not "vulnerable to legal and psychiatric control" because of autism.
4) If you are self-diagnosing instead, then (depending on symptoms) you could be missing a serious condition like epilepsy, schizophrenia, a genetic disorder, or lead poisoning. People with real autism are also more prone to developing certain comorbid medical conditions, like epilepsy, GI problems, or OCD for example. If you're already under the care of a doctor with some knowledge about autism, they could catch these conditions sooner.
5) Autism and gender dysphoria have been proven to have some sort of a link. There are many theories behind why this happens. Some of these theories say that autism and gender dysphoria have a shared cause. Some say that autistic people are more likely to experience gender dysphoria without actually being transgender. Some say that gender dysphoria can be a manifestation of autistic traits. Some hyper-woke people believe that any studies about transgenderism and gender dysphoria are inherently discriminatory and should not happen. This leads to a lack of beneficial research. It is not "fearmongering" or "anti-trans" to believe that there can and should be more medical research about how to best diagnose and treat gender dysphoria. Autistic people may be more likely to be harmed by this lack of research. Sounds pretty ableist, Devon.
Most FtM people who can't grow more than a few neck-pubes will just shave, because being clean-shaven looks more masculine than that. Stephanie is a cisgender non-intersex woman with bad genes or hormone fuckery or something, so obviously she doesn't care about looking masculine.