world chat became a thing in private servers as a way to show people are playing, people didnt want to feel like they was alone. but in official it was always possible to create public channels and people did and shared them on forums.  i don't understand the logic behind removing it though. "looking for group" in retail was the world chat.  
	I will also point out, the game may have not changed but the way people use the game has and an important thing for private servers is they want people to connect because it feels busy, and that makes people stay.