The key concerns me a lot. It is not like other keys in-game. When you look at it in the menu it has an amount associated with it. It's probably a currency of some kind. I'm expecting a temporary event similar to the carnival quests.
I'm not too fond of the quests. BKing gets way more love than PKing. I just hope I'm wrong and these keys are more useful than for some "free" cosmetics. Whatever it's for, it's clearly not ready, yet. If it takes or has taken any time away from NGS development then whatever is coming has to fill some big shoes to excuse itself for lost time.