You already have to unlock it. You have to get 460 ilvl.
If you start hiding things behind quests, you'll find a large proportion of players just won't do it. I remember the Karazhan chain, how my ultra casual guild members didn't know anything about it and we had to run them through the whole fucking thing every time we needed more people. Those are the people LFR is aimed at, those are the people least likely to bother with a quest chain to unlock things.