Nooo, not just for the party! It needs to be like, game wide. Like a staff announcement. It can even come with the badass gong sound! Amiright?
Actually, I can expand upon that stupidity and make it feasible.
/raid <boss>
Engine checks if boss is currently spawned. If it is, everyone ingame will get a message in all red letters.
"RAIDING TIME MOFOS! TIME TO PWN THE <insert boss>."
If it's not in, message isn't sent.
Not too bad, and before it's said, who actually spams stuff nowdays anyway, considering some bosses are always in
The message, although badass, I guess could be changed to better suit the game. But yeah, also keep the idea about the gong sound. A raid warning NEEDS a gong sound.