The look of DS was one of the main hooks. I am worried it may be like the comic. This was loyal in the spirit but I missed its special fashion. I call them "hyborian-punk".
And the lore.
And about the new regions after being "unlocked". I don't want anything like the "syndrome of Boo", like in Dragon Ball when a villain is defeated and then later a new stronger enemy appears.
With a good explanations many new classes or races could be explained, even the shadar-kais. But would you allow shamans, wardens (primal defenders, the paladins defending nature) and seers? Monks are possible, most of them learn in the gladiator arenas as pit-fighters.
Other matter are the genies who live in the elemental plane and theoretically could try to invade Athas.