“Test Your Mettle” Achievement Now Unobtainable – Please Consider a Fix

I think it's weird that they tied a trophy to a time-limited event, while leaving the rest of the game online.   I can understand trophies that are tied to a multiplayer where the servers have been taken down (eg. Battlefield 2 & 3) but this one is really strange.   It would be great if they introduced a workaround to fix it.