Global Chat could be worth trying out. Worst case scenario, people can just hide it. Maybe put some restrictions on it so new characters can't use it right away, maybe you have to be at least level 20 or something. Make a new rule in the TOS that Global Chat is for discussion only, no ads for venues or events.

One concern I'd have is that it would be way too busy. It'd be like reading a popular streamer's Twitch chat or something, stuff just flies by at the speed of light, it's impossible to read anything. If that ended up being the case, I think it would not really have any value.

I think somebody also mentioned the chat bubbles idea in here too, that would be fun for those who want it. Again, if you don't like it don't use it. It would probably be an opt-in feature anyway.