I'm sorry, how long has it been since Vanilla? Oh right, 8 years. I find it quite hilarious that you deem the transmogrification of a few sets of gear be game destroying for you. That's quite a shame that you lost your tier 3, but it sounds to me that you never put your tier 3 in such high regard, why didn't you just keep it in your bank? Oh yes I'm sure you needed the bank space am I right? Those 8 slots were much more important than your tier 3. It's no ones fault but your own for vendoring your tier 3.
What I'm getting at is you just want your Tmog to be that of prestige and "sparkle snowflake edition", as for me I want my Tmog because it's something I've always sought after, but never could grasp it. There are far less players from vanilla with said prestigious achievements playing than there are players right now, I don't see the reasoning behind gating content to the smallest portion of players. It's simply stupid.
This saddens me that this is the only way you describe where you can determine the validity of someone who has been playing since vanilla. There are plenty of other ways.It bothers me deeply that I won't be able to give a nod to other players that played in Vanilla anymore.