From my experience, I haven't had issues dealing with coverage for myself (with providers located in NY, NJ, and PA) for therapy with a psychologist/social worker (assuming psychological appointments are actually covered by the provider) or with seeing an endocrinologist. If there is, speaking with other folks, I've found that these people can simply get around the problem by submitting a different diagnosis to the insurance company.
However, drugs are another story. I'm currently on this whacko obscure Japanese Provider that uses Aetna's network for billing purposes called Nippon Life Benefits through my mom's employer (...yep). With them in particular I've never had issues with them covering my appointments so far for about 3 years, but once they did decline to pay for estradiol...of all things due to "sex incorrect for treatment" (still need to change my legal sex...kinda don't know why I haven't at this point). Mind you, they were still covering the spironolactone and the progesterone (both far more expensive drugs...so yeah, what?

!). We just dealt with it by disputing the matter and it went through.
Just check the health exchange otherwise I guess. Oh, and make sure whatever provider you go to (endocrinologist and gender therapist) is in your insurance's network.