To put it bluntly this will never happen because they want the game to appeal to the masses meaning all ages old enough to understand it's content. Also remember, MMO games tend to have 2 separate rating systems with one being the "pre-programmed" content and the other being "online interactions rating" wich to a point ends up being NR because it varies so much. Now would it be nice to have such content? For sure! An age verification system and extra fee would be ideal. Sad part is, there is always a way around such systems. I guess in the end, it's up to the parent to control the type of content their children have access to.