This is just a quick idea and if i'm in any way wrong please tell me. I din't raid in tbc so forgive me for being ignorant etc.
But aren't the Vials of Eternity given to Soridormi? and more overly could this be the reason she is killed since one vial made the sunwell so surley having two could easily be used as a boon for an evil plan etc :P
Anyway for all i know she might have destroyed them already etc. just an idea wonder about your thoughts/ if this is bollocks or whatever.