Yeah, this ended up being an unstructured mess. There's a summarized version at the end, but the rest contains reasoning and some hits at the unreleased CoC, as it has been presented by the two answers posted to two different resignation posts on other metas.
What do you want or need us to do so that you feel welcomed?
The new CoC as it has been presented this far overcomplicates it a lot. Speaking for myself, I'm perfectly fine with "they" instead of a random gendered pronoun, and I'm pretty sure most people are. SE isn't built up as a social media where gender is listed. Even if it is, there's far too many variations to properly cover it.
For an instance, there's people who don't have pronouns at all, and prefer to have their name used instead, there's people who change pronouns daily, there's people who use multiple pronouns, some who use all, some who use all except one or more, and all kinds of variations in between.
My point is: don't overthink it. Most on-site interactions actually don't touch pronouns, with a possible exception to meta sites. Personally, if I'm in doubt, I use "they" or avoid pronouns entirely if I'm on main or meta. Chat is different, and I'll rather ask if I need to. Using names is, as far as I know, the variant the fewest amount of consider offensive. I actually haven't met anyone who has felt offended by name use (provided it's not deadnaming, which is bad either way, but doesn't really apply online).
Generally, if you're in doubt and it makes sense to ask (it would likely be considered noise on main/meta), ask. And even after you've asked, I doubt anyone minds if you fall back to their name. Speaking for myself, I like hearing my name from time to time.
Do you want us to proactively ask you for your pronouns or other biographical or identity details before we engage with you?
If it doesn't make sense to ask, no. Again, chat is a lot better for these types of things. Optimally, we'd have a system for adding pronouns to names, but that gets complicated fast with all the variations. Not to forget that some people don't want to list their gender, and requiring it can ironically be unwelcoming too.
While a lot of people know their pronouns, there's still people who aren't sure what they are, and prefer to not list anything or even see that option. Not to forget people who aren't out of the closet. Both these might be a minority of a minority, but they matter, and their problems are real.
This part needs its own paragraph because of a misleading definition elsewhere; "they", aside the plural use, is widely regarded as a gender-neutral pronoun. Now for the misleading definition; "they" does not have to refer to non-binary people. I know some non-binary people, one of which is fine with he/she/they. I also know one who prefers it/its, but who's fine with "they" too in the sense that using "they" isn't considered offensive or hurtful. Non-binary people can use all kinds of different pronouns.
Moreover, non-binary isn't technically a gender - it's a spectrum of gender identities that include all kinds of identities. Quite literally, non-binary means something outside a binary system (here: male and female). The "implications" vary from person to person, and I don't have a chance of listing all the variations. I actually don't know all myself - more on that later.
Honestly, I doubt anyone will call you unwelcoming for using "they". Personally, I find that a lot of people just assume programmers here are male, at least among new users. "sir" and "bro" is also thrown around an unnecessary amount regardless of the receiver, and this practice needs to die in a fire, preferably yesterday.
Misgendering is a slippery slope. There's some people who can't be misgendered (that's those who use all pronouns, and don't really care which are used). Some people use multiple pronouns and can be harder to misgender (if one or more fall in the "binary" pronouns).
Personally, I only consider misgendering a problem if it's repeated, and it's clearly malicious. That being, if someone uses "he/him" about me, I'll correct them. I don't like it, but I'm not going to hate the other person for that. Note that not all people take this approach; some people are hurt the first time. I've gotten a bit of a laid-back approach to it. However, repeated use in a way that's pretty obviously an invalidation attempt is directly hurtful.
Again, this isn't complicated: listen to people. There are a lot of unique approaches to pronouns out there (trust me - I'm in multiple LGBTQ servers on Discord, one of which is a server exclusively for transpeople and non-binary people).
That being said, no one is required to learn all the pronouns - there's a lot of them Live site: https://pronoun.is/all-pronouns. There's also no point in learning all of them, but if someone tells you they use a pronoun you haven't heard before, all you need to do is remember that the person uses that pronoun, and you're good.
What do you want or need us to do so that you feel welcomed?
- Listen! Discarding people's pronouns or identity because "it has to be proven" is offensive. If someone tells you their pronouns, accept it and use it. Some might sound weird at first, but a lot of things sound weird the first time they're heard.
- Don't use gendered pronouns without clarifying first. Or, as written more elegantly in the first answer - avoid assuming gender. Prefer gender-neutral language or names if you're in doubt.
- Remember that some people don't use pronouns. Listen to them and find out what they use instead.
- Make changes to the CoC - but please don't make it so strict it fails to include other members of LGBTQ who may not be as visible (including, but far from limited to people who are still figuring out their identities, people who use multiple pronouns, etc). Allow names, allow "they", but make sure it doesn't allow for intentional misgendering.
- Flag behavior that's clearly abusive. Under this comes a second request (albeit not for users): make comment moderation tools better for everyone to help find abusive behavior and mitigate problems fast.
- Don't be like SE. We have feelings too