I still believe SuperBot still has a trick up their sleeve, Paul's source is probably surprised they said 20 too because he probably knows they are in the game, SuperBot just said that to track down Paul's source. Believe what you want and maybe I am setting myself up for dissapointment, but either way, " I JUST GOTTA BELIEVE!!"
I'm remaining optimistic even with my practical mindset. With this new info care of Paul, we now know that these characters were considered, at least. And with some making them through more of the development process than others.
I think Superbot still has some surprises left.
Plus, we still know David Hayter had his voice casted for the game. It'd be weird and a shame for him to have to do all the voice acting and not wind up in the game. (Unless he's a 'minion')
Anyway. Just a matter of time before we know everything. DLC plans included. So stay patient, guys. Only a few more weeks