Tier 3 tradeing post imidiatly after hit lvl 100

Is currently bugged. Where i have 1/3 at exalted. and 10 guildies have 3/3 andit shows they earned the achivment.

They got theirs from logging into ever character both horde and alliance they have on their accounts. 

So log into every character you have before WoD drops that way when you get to 100 you can unlock your first tier 3 building immidiatly