Honestly.... increasing graphics is likely a very low priority since the return on investment isn't going to be that great. Consider the amount of time and man hours it would take them to do this for all the appropriate areas, then realize that character and clothing models will look out of place if areas are getting a graphic update but the avatars are not, then ask yourself are people quitting the game over graphics, and would more people start playing the game who are not currently if they invested that money? Also you have to ask is putting the time into updating the game's graphics worth the time that will be taken away from developing more playable content as a result?

Me personally, I'm 100% fine playing with older graphics as long as the gameplay is smooth and the content is engaging. Graphical quality isn't a high point for me, so I hope they don't spend too much effort on strictly visuals until that is starting to become a risk of making the game less enjoyable overall.