It's sort of strange that this selective pronoun approach only really works in an online context and doesn't scale appropriately to real life interactions, to the point where pronouns become useless as an information compression and so we would be better off not using them at all and just use proper nouns. But this is where it gets funny because that's easiest in most online comms with the use of @.
It's quite clear no one has any idea what they are doing.
I see it the same as telling colleagues they are fat etc. It is rude. If you keep it up when they ask you to stop likely you get fired, even if you are right.
Anyway, in my opinion if they make a bigger deal out of it than if when you call people fat then it is just politics. But I still wouldn't do it myself, just like I don't call people fat even if I think they are. If they push me then I will tell the truth, but if they push me to hear my opinion about their pronouns or gender then it is hard to say that it is me bullying them rather than the other way around.
Edit: But I think this was originally about being forced to show your pronouns online. Not sure I'd like that, seems pushy and bullying to me. I'd rather people not have that information, even saying they/them is information that I am not comfortable showing my gender, why would I want to give people that information?
The way I see this, my sexual preferences has nothing to do with software development. I know a bunch of people disagree, sometimes even claim you can't develop software without sexuality but that's actually discriminating against asexual individuals and often against people on the spectrum that are not in able to express their feelings. It's all deeply troubling.
In my language (non-indoeropean ) there is no difference between he and she, that regularly puts me into trouble for somehow "intentionally" mis-gendering others and there's never any lenience expressed towards me for that.
Even if you're against trans people, in an online forum, normalizing calling out pronouns allows cisgendered women to say "I'm a woman and would like to be called as such" without it being disruptive or cause men to view her as pushy.
All the more reason to explicitly call it out ahead of time, so they can be certain to use the right ones. Why would it be pushy, -especially- if there's reason to believe someone will use the wrong ones?
Really, I don't understand the objection; we pre-emptively give our names to people, for all the same reasons we might give people our pronouns.
It's quite clear no one has any idea what they are doing.