What I always found interesting about the wording on Blizzard's policy is that they don't "currently" have any plans to remove the drakes at all, but they're keeping an eye on things. It makes me wonder if there's an ideal percentage of guilds or players they'd like to achieve the drakes each patch, and that numbers were short in Naxx and still short in Ulduar. The Naxx-era Glory of the Raider (heroic) was certainly uncommon and, for a competent guild, hinged almost entirely on their ability to get past the RNG-riddled and sometimes-buggy Immortal, then said to be the rarest raiding achievement in the game. For Ulduar, my guess is that achievements like Firefighter are probably the biggest stumbling block, although fortunately the achievements required for the meta are more dependent on skill and less dependent on RNG than Immortal. We'll keep an eye out for you, but for the moment, raiders, keep plugging away at those drakes.