I can confirm that it works, I have completed it. And I have to admit that this is the plan of a brilliant criminal mastermind: add a new achievement for dead content, after noticing that the achievement is bugged (I doubt it will take a week to find out), wait for the content to be even more dead ( only one instance active at a time, and unfilled), to fix it; and the most Machiavellian of all, tell us that they have added all that kitten work to us, to make our work easier. From Arenanet to the James Bond saga