All There in the Manual/Quotes
Sadly, as long as raids remain isolated from quest progression outside of them, stuff like this is what we get; rather than tell us a story in the game itself, they plaster stuff on their web page so that they don't have to write the story into the actual raid.
It's extremely haphazard, and results in things like the unlikely-to-ever-be-updated encyclopedia on the official WoW site that they added to explain all the TBC stuff that they didn't feel like comprehensively explaining in-game. The resulting sense of detachment feels like watching a movie without sound and being expected to download a transcript at home and read it to get the character dialogue.
Secondary content should complement and enhance the actual game, not outright replace it.
"Reassembly is the reverse of disassembly""...except you swear in different places."
—Parody of Haynes repair manuals, original source unknown.
"RTFM"—Well known admonishment to electronics users.