This has me thinking that we might not be seeing any brand new Classes for, at least, the duration of the Worldsoul Saga. Rather than trying to develop and balance an entirely new class, they might instead be planning on just adding more Hero Talents to the current classes. This lets them work in concepts and themes that aren’t deep enough for a whole class (Dark Ranger, Necromancer, etc) while, as you say, are easier to balance by just turning the knobs on one or two core abilities.
We’ll most likely not see any effects of whatever decisions they’ve made in this regard during TWW. I’d wager it’ll be Midnight where we’ll really start to see what kind of direction they’re taking the game.