I don’t give a damn if the costs killing the big 3 are for past retiree costs or future retiree costs. They and the UAW negotiated all of them, and they have to live with all of the consequences.
If they don’t want to live with all the consequences, then they have to give up some of the retiree benefits. They can figure out how to do that amongst themselves. I don’t need to hear or negotiate the details. If they don’t want to clean up their own mess, then bankruptcy can do it for them. This is what should happen to any normal business.