In general we don't really need models or textures tho...like there's enough models for 2 updates or so...adding said model, animating it, writing the rendering code (if its something more special than just a humanoid), adding its AIs and special features, testing all the above all of those things are where most of the time goes in...won't even start with the hell that is adding structures....
so if we got more, that doesn't mean they'll get added or anything...they'll just collect dust until their time comes and nobody wants to waste their time and effort on something that will go unused for months or years (understandably so)