"TBA" Client Popup
If you've recently logged into Hearthstone, you may have received a popup titled "TBA" along with a description of the same value. It would appear that something on the server-side of Hearthstone has been changed which is now awarding achievements which were not fully implemented until the most recent patch we found earlier this week on the servers. It is likely, although not confirmed, that the patch has been applied on the server and clients should get it soon.
If you have Warlords of Draenor Digital Deluxe, or a BlizzCon Virtual Ticket, it has triggered these achievements for your account on login, yet, the card backs are not yet in the game until the client updates. Your card backs interface also defaults to a blank spot with no name, indicating something is there but you cannot choose it.
Rolkyr says that the situation is being looked into. Zeriyah has issued a statement on the matter.
Quote from Zeriyah
Sorry about the TBA message! We're working on implementing the Blizzard card back and Warlords card back, but some switches were flipped a little too early.
Getting the TBA message isn't a bad thing, and it won't prevent you from getting those card backs. It's just a visual error. The only thing that you might experience is once those card backs go live and are available to acquire, you will not get that notification again. The cards backs will be waiting for you where all the other card backs live - in the 'Options' menu.