I don't know what is making Charlie think this is the case.
First of all, Jones isn't that good. He isn't a starting caliber NFL QB from anything that I have seen.
Skip Bayless, who loves OK, said that he has seen plenty enough of Jones to know he will never be a starting caliber NFL QB.
When Jones was on a team with superior talent, he put up some big #s. But like many QBs in that situation, if he didn't have the superior talent, he was below average. I don't see a guy like that becoming a good NFL QB.
Charlie may be right that in 2 years, Pgh will need another QB (as Ben could be just tattered by them or worth more than what Pgh is willing to pay) but Jones won't be who it ends up being.
Jones is simply there to provide a back up that isn't 40 years old. I doubt he will ever develop into anything more than that.