Is there any real need for them? Champs and Supers are all part of the game, the only reason for a global announcement when there is a super is to announce to those who hunt bosses to rt/trans/tele to find it.
The global announcement gives the advantage to the higher levels who have the ability to get their quickly, pk the lower levels who are already in the cave and grab the kill. If there was no announcement everyone has a chance of finding a super/champ boss and get drops without worrying as much about being pk’ed and lose items. Most people are in guilds so if the boss were to strong to kill they have the ability to call their guild or alliances guilds to help out...
The global announcement gives the advantage to the higher levels who have the ability to get their quickly, pk the lower levels who are already in the cave and grab the kill. If there was no announcement everyone has a chance of finding a super/champ boss and get drops without worrying as much about being pk’ed and lose items. Most people are in guilds so if the boss were to strong to kill they have the ability to call their guild or alliances guilds to help out...