I'm seeing a lot of ppl to panic just because they can't deal with Jaina before the release of CoS. People just seem to forget you can clear CoS after they have finished BoD just like in previous expansions:
In Cata ppl focused on first raid at time during launch.
In MoP HoF was opened after only ~100 guilds killed HC Will of the Emperor, not a big deal.
ToES was opened after only ~300 guilds killed HC Will of the Emperor and only 48 killed HC Grand Empress Shek'zeer. Not a big deal, guilds just killed went to new instance after first one was almost done.
Same thing in WoD with BRF, only ~420 guilds killed mythic Imperator Mar'gok before the release of BRF.
And let's not forget Helya and Nighthold.