The biggest reason new players try out Octo wow and leave is that they can not find anyone to dungeon with as they are leveling. So as a solution, allow level 60s to down rank inside of instances to the level of the instance mobs and participate with these new players. AS A REWARD the players downranking can get a token upon completing the dungeon via looting final boss or w.e. THIS TOKEN can then be exchanged for faction rep, gold, cosmetic items etc.
People want to dungeons as they are leveling if they cant, they will leave, this I believe would solve or at least help alleviate the problem.