They still do this, but a little bit differently. They cook all the food and have it in tubs in a heated cabinet. When you order the food, they assemble it while you wait, but it's already been cooked and sitting there for a half hour. The only meat that is cooked to order is the quarter pounder burgers. I'm guessing because they are the most expensive. Everything else from eggs to chicken to McRibs are all cooked ahead of time.
They just keep it out of view of the customers. If they don't see the workers grab an old burger from under the heat lamp, they will think the food is getting made fresh. In reality they are basically eating food that has been sitting under a heat lamp.
Here's a trick to get fresh food! Tell them that you don't want salt on your fries or burger, they will have to stop what they're doing and make fresh food specially for you! What a neat trick! The teenage kids who work there love doing extra work so your garbage fast food can be fresh. They totally won't fuck with your food because you demand special treatment. And if you ask for fresh nuggets, they just take old nuggets and drop them in the fryer for about 15-20 seconds to get them hot.