Support Forum Agents. The Blizzard moderators of the Support forums. You’ll recognize when they post because of their blue text. Almost GMs, but not GMs; they can do research and sometimes fix little things, but mostly they make sure the rules of the Support forums get followed.
In this case, they’ll probably close this since it was inappropriately resurrected. This instance of disappearing store transmog is not related to the earlier one, so this thread isn’t really appropriate for this bug, and there are other current threads that you should probably be contributing to instead. Among many others: