Simple suggestion:
The chat system should detect properly written nicknames in the global chat.
example:
/w Skula1975
If Skula1975 isn’t on my follow list or friend list , the chat will say, that this person does not exist and that I never met him!
/w Skula 1975 (this is a case of incorrectly written nickname and such claim is true in this case)
If the subject Skula1975 isn’t ONLINE and is actually OFFLINE , we should get a notification, when we send a private message via chat, that this person is UNAVAILABLE!
So, if I write a proper name, the chat should 100% add it, even if I do not have it on my friend or follow list!