Since that questline actually awards quite a bit of artifact power, I'm pretty sure that a lot, if not all of the major guilds have done it or at least will have done it before that Wednesday you are talking about.
I have to agree that a pre-quest does sound antiquated and would probably aggravate a lot of the "I'm only here to raid" WoD crowd. BUT: If there WAS a pre-quest, this one would one that was quite nicely done. Nice story arc, culminating in the Nighthold (and explaining why we enter through the sewers again - which in BT during TBC I never really understood), and offering quite some diverse quests that were mostly interesting to do. Only problem was the moot running back-and-forth through Suramar, but that probably is because of lore / immersion reasons.