I think there should be a seperate button to message someone in case you want to talk privately (share info that you don't want other people to know/ if you don't want people to know what you're talking about. Either they can add a button that says PM (private message) or they can add a command that can be done in chat for example:
/message (username) (text)
and
/reply (text)
Thanks for reading and share your thoughts about this idea correct me if this is ruled out

