If you should encounter the bug that the event does not start.
The easiest fix is to get your characters butt into a different phasing. And it should be possible to restart the event by talking to Taoshi
How to do:
1. Queue up in Groupfinder, for a custom Pre-Made group e.g. at the time there are many groups around farming in Dalaran Sewer... Or a Fishing for Mana group.
Just make sure that after you started the event, if it is a raid to leave it otherwise you will not be able to do the quest due to the raidrestriction....
2. Ask a friend that is on another server-Categorie and/or Region, to shoot you a groupinvite...