Stygn

So last night i was doing Power to destroy (RFC) but when i was on my way trying to turn in the quest Varimathras in UC aswell as sylvanas had been killed, it couldve been prior to me coming over there but im basing it on that it had just been killed sort of deal, could this be looked into? And im unaware of if this would be the correct area to post such topic but i do suspect it of being a bug. unless they have like a 24 h respawn time.