Through a blue post of blizzard poster Bornakk revealed that the rusted and ironbound proto-drake rewards for the normal and heroic Glory of the Ulduar Raider meta achievements will be removed at or after patch 3.2. The date haven't been determined yet. Blizzard will warn player this issue one month in advance.

These mounts are rewards for the top tier of raiders, since these rewards are designed for such high-end game play, Blizzard plan to continue removing any similar rewards in the future.