Slang is supposed to exclude those not in your group this seems similar in action. In a way it's bullying since an agreed upon style is now considered old by s

Slang is supposed to exclude those not in your group this seems similar in action. In a way it's bullying since an agreed upon style is now considered old by some but if everyone is not aware of the change how does everyone communicate respectfully? It's fundamental communication that both sides understand each other's meaning.