They can fix this by changing how gear distribution works. You get honor gear from random BGs, then you only get conquest gear from rated and you cant que for rated until you have full honor set and likewise you cant que for random BG once you have a full honor set. This effectively creates 2 brackets with a much lower ilvl disparity possible between the players.
But honestly they have much more problems to fix for PVP other than ilvl. There is way too much CC for pvp to be fun. The current burst meta would be fine if they halved all CC duration.