Yeah, from what I have heard/read, the development of a show model involves some real serious work, and therefore I really don't think we're going to see a group of new characters who will only be used for a couple of episodes. In fact, I think this is nigh on impossible to expect. Even new character Magnus, for example, is a 'retool' of an existing model.
The number of character models speaks volumes about the difficulty of creating these... we will have 65 episodes of Prime by the end, and there's a total of about 9 Autobots and 12 Decepticon models, compared to say what 50+ Autobots alone by G1 episode 65??
It is true that there were some 3D models used for the Predacons in the chambers, but these are probably very simple models that are not nearly as hard to create (e.g. only rudimentary movements, definitely no transform). Plus for those they didn't zoom in on, may be even simpler with 2D to 3D trickery.