Nostalrius Begins - Quality wow vanilla realm (1.12)

I can't get it.

I'm lvl 50 with my Paladin and went to the Trainer to get spells and the quest but it didn't pop up nor the followup in the WPL. Now, since that questline is a really nice one and elads to a Sunken Temple quest which gives awesome rewards I'd like to be able to get and do it.

Is there a way or is it bugged and/or not available?

Sunken Temple quests aren't implemented yet. IIRC they're not supposed to be in the game until 1.9 or 1.10

Aren't we on 1.12 already? Will it be implemented?