I would also say that this progression is way to much to soon. You should have good passive range of movement before beginning some gentle weighted exercise. You should not have to push into or through pain in any shoulder injury as I have usually found that completely counter productive. Hanging from the chin-up bar is a full body, end of range position on the GH joint and this would be a huge stress on the shoulder structures.

Basically I would listen in this case to your surgeon. They saw the damage, the did the sutures and it's there call. Make sure you get some good communication going with the PT and ask them for reasons for why they are prescribing each exercise. They may have a good justification, just I can't think of one right now?!