I can only hope it does hurt those pensions--it can leave them peniless who threw it all into oil speculating for all I care, pushing the price up hurts the economy long term because it hurts the purchasing power of ordinary Americans. This is the equivalent of Pete Rose betting against the Reds (sports fans think of it that way), and that's the straight dope...
Most people with pensions don't choose what to invest in. The fund managers do it for them. Ordinary Americans are exactly who will be hurt most.