They did implement some sort of "raid warning system" but the concept itself is very cumberstone that no one bother to use it. Those icons you're able to place over yourself and mobs should help in that respect but with how long it takes to execute those commands it just doesn't beat either typing it or saying it on a voice chat. It would be nice if they are able to implement better methods of communication in combat that doesn't require voice chat since some players just don't enjoy playing that way.