Seasonal Reward Tracks.
You make sure all those rewards stay in the hands of PvPers, of Top Rankers even.

But active ones, and constatly rotating, so new players can jump anytime to the reward track of their choice. That way if you see -And you will see them way more often- a PvP mount or glamour you will know is in hands of a legit and active players. Anyone who doesn't participate of the tracks just loses access to those, just like in most competitions where you win once, but next year you gotta compete again if you want to keep calling yourself a champion.