The union was caught in a global hurricane, and they managed to come out of it with minimal structural damage. They preserved key principles; they gave up some money.
This was difficult for the union to do, but the union is being pragmatic. Its goal is to preserve jobs. It realizes the severity of the situation that GM is in.
The union has very painful choices, but it's managed to preserve important principles in a very turbulent environment. At the end of the day, UAW retirees will still have paid health benefits. Less than before but far more than most Americans have.