I'm of the opinion that the only reason CJ is still on the roster is that it would have been cost prohibitive to cut him at any point prior to this season. After this season, it becomes much more palatable, financially, to do so. I expect this will be his last year unless hes willing to take a pay cut to something commensurate with his performance.
I would say the last thing Dave wants to do in the regular season is give a guy who has never made any real money 15-20 million guaranteed. That kind of thing can lead to all kinds of "distractions". Better to keep him playing his ass off for that money at the end of the season.
He seems like a pure speed rusher type of guy. He either gets by his guy based on his initial burst of he gets stonewalled. Regardless, its great to see a young guy doing anything positive from the DE position on this team and having a great speed rush is definitely something you can build the rest of his game around.