Non-union retirees get their coverage under corporate benefit plans, which are non-contractual. The retirees who have to worry the most are those whose former employers subsidize their coverage. Those subsidies are likely to disappear. The company may then still offer the coverage, but the retiree will pay full freight.
Contracts? Ask the bond holders of GM what a contract is worth. Ask the GM and Chrysler dealers. The Obama commies will ignore any contract that gets in the way of their agenda.