i'm good with this move even if they don't cancel out the compensation, a better pass rush gives them a better chance to win the super bowl, gotta push some chips to the middle of the table. As you said, he is eligible for a comp pick if he signs elsewhere as long as the Eagles aren't shopping as well.
That said, the difference between the Jets third and the Eagles third is pretty significant, so i'm happy the pick they gave up is their own third. Win Win.