Actually, I think it will be the offensive line and not the receivers that will contribute to a breakout year for Jarwin. At least starting out, Dak is going to need a safety valve and that should be Jarwin.
I think Jarwin has the potential to be another Jay Novacek, another TE that was more a TE/WR tweener. The Cowboys always had that bigger more physical blocking TE when they felt Novacek might be a liability on certain plays, although he learned to be a decent blocker.
Jarwin can get downfield, beyond the 2nd level so he can run well with the ball, 5-7 catches a game can add up. I actually see only two players get over a thousand yards this season and I believe one of them will be Jarwin.