I think the aim is to separate the player chat from character chat. Players can chat freely on discord, the forums etc. but in game they will be conversing as their character. If you look at the communication dev diaries it does seem likely that most in-game player interactions will follow a multi-choice dialogue tree.
The only thing that person would be able to resort to In game would be deviancy, for which the community will have every opportunity to punish or exile them.
In the meta-game, discord/forums, just block them or ignore them.