Humans have to make basic baseline assumptions when interacting with people. This is normal, and there is no majority voice in the community that advocates for increasing diversity that is saying you can't do this. The 'DID YOU JUST ASSUME MY GENDER?' stuff is is an out of the norm reaction that has largely been co-opted into a meme by those that are against increased diversity as an attempt to ridicule it. The same with the 'identifying as an attack helicopter' crap. There are definitely extreme voices, but they are a small minority.

The goal for those who are pushing for diversity and continuing to combat sexism, racism, homophobia, transphobia, etc. is not to alienate everyone and force them to never believe anything about someone's race, gender, etc. unless explicitly informed. The goal is to make sure you respect that sometimes appearances don't match reality.

I have a lot of good friends. Some of them happen to be trans. I have never seen any of them get upset at someone who misgendered them prior to transition, as long as they made an effort to correctly gender them after being informed. During transition, largely the same. Post-transition it's usually quite obvious, but I still see them exercise patience, at least at first, if the person's demeanor isn't hostile.

As for bringing up the topics - they might not want to rehash it with you, or anyone. That means that if they ask you to drop it or are otherwise expressing discomfort with the subject, do so. Don't debate it right around them (and I'm guilty of this one!). But that doesn't mean don't discuss the issues. They can ignore comment threads on the internet they don't want to read, and those of us not facing those issues need to be cognizant of them and discuss them. In person, not so much - especially in the workplace, where they might not have any way to escape the discussion.

The goal isn't to be the thought police. The goal is to be courteous to others.