Champion Subclasses

Wondering if (and hoping to receive some Riot correspondence on this) the new Subclass divisions are going to play any part in the new updated client when it hits alpha? Will champions be divided into the newer, finer classes? Or will the main 6 remain? Support is technically removed since the introduction of the Controller class, and Assassins have become part of the new Slayer class.

Also, will Champion Mastery Level titles (Assassin Lvl 7 Deathmaster, Marksman LVL 7 Sniper, etc.) be reintroduced for the specific subclasses? Seems necessary, in my opinion, since some classes are being completely reworked into a subclass of a higher division.

I loved the separation of the classes, and just want to know if they actually mean anything.