Imo, it wouldn’t even be that hard to implement.
1800 could still be the “elite” set for casuals
2100 weapon enchant
2400 Elite set (with maybe lighting effects added to it. Think of the difference between heroic and mythic sets)
2700 new armored Glad ground mount?
Obviously they’d hafta add in other stuff (pets, toys, banners? etc) for other ranks like 1400, 1600 etc. But that would probably take away from their precious store items lol.