wasn't trash talking. It isn't trash talking when it's the truth. Jackson has been getting away with big plays on deep routes because he goes largely untouched. Just look at the films. What Jenkins was trying to say was that the Cowboys need to be more physical with him and not take him for granted or else he'll burn you.
If anything, Jenkins was paying him a compliment.
We'll see how the defense responds. IMO, I'd use almost the same game plan that the Cowboys used against the Saints. Invite the Beagles to run the ball as much as they want and pressure McChunky as much as possible. Just don't let him get comfortable in the pocket and allow those 3 receivers to run wild. Keep them from making the big plays, they get impatient and, eventually, frustrated.