By assimilate, I mean blending in as a member of one's new sex. I don't mean blending in as a cis person.
I have never dealt with people in the LGBT community hating men or masculinity. Half of the LGBT community is male and that male half will talk shit about you if you're not masculine. I've also never had someone tell me I was better than cis men, or that I was welcome in some "AFAB-only" space, or had anyone judge me for not wearing a skirt and lip gloss or whatever the fuck. I'm not saying those problems don't exist, but they exist in very niche places where it's strange for a man to hang out anyway.
What happens is that you guys go into the same sort of female-dominated queer spaces that you did pre-transition and then start complaining that the people there have trouble seeing you as a man. Start hanging out with men, or just anyone who isn't a liberal. Your queer feminist book club is not going to like men, and if you go in there acting exactly like every other woman then they will begin to believe that trans men are just like them and not like men. It's always the dudes describing themselves as "straight binary masculine men" who whine about this shit too. Most of the time it's not just you being openly trans that's causing people to treat you this way.