I can't find this setting, but it would be great if it were possible to disable the chat feature.
Edit: deleting because this is already being discussed elsewhere.
Would like to see some enhancement on chatbox
Chat box cannot be directly access from notification
Chat can only be initiated by the small chat icon below user avatar, maybe that icon can be added to user profile.
Haha, thanks for the link @trevor - was about to post the same thing