It doesn't. But that doesn't mean we should just slap on a release date for the sake of slapping on a release date, and then release the game in whatever state it happens to be in at the time of that date.
Making a game is a delicate undertaking. Especially one the size of wow with virtually hundreds of thousands of "moving parts".
Look at it like its a tunnel of which you have no clue how long it is or what speed you're going at.
You can't tell you're nearing the other side of it until you can see the light at the end of the tunnel.
They've indicated they need time. Give them that time. Whatever comes next is anyones guess.