I've thought about this and Discord before because it's so easy to use.
There have been various iterations of NA chat over the years - official and unofficial, and I think there are good things and bad things about it. Sometimes I do think it would cool to just have some casual discussion and actually 'talk' on a more real-time basis than the forum.
Maybe the compromise, is that we just don't get too hung up on the official vs. unofficial status. I wouldn't mind to start a Discord for example, and just leave it open for people to chat and hangout. It can be separate from NA, meaning, punishments and actions don't necessarily transfer, but if someone is being racist or hateful in the chat, whoever manages the chat should just ban them. So it isn't necessarily that the NA mods need to moderate the chat, but whoever has the 'power' in the chat system could ban people for being horrible.
I think the practical crossover issues could occur because people would get upset and/or form opinions of people and that resentment or tension would likely carry over to the forums occasionally and manifest negatively at times. And I suppose the issue from a staff/moderation standpoint here, is that if that becomes a trend that we have to deal with, it could be some extra work. So despite the technical presentation being it is separate, if arguments are brought here it could be negative.
I guess I'm kinda rambling a bit as I tend to do sometimes, but I do see the appeal of chat, and I would like to think people can be somewhat 'not-super-hateful' on there. Some people just like to troll wherever they are, so it is hard to manage sometimes.