Cause that isn't what I got from it; term negotiated and contracted prices aren't "price controls." The suggested fix here is industry standard practice in many other business-to-business markets where the buyer selects a seller based on not just on how much they are selling it for today, but how long or for how many units they will guarantee the price for. Which is what is being talked about. AKA food supplier negotiates a price and guarantees it for a year.
So, its not a bad plan. Forcing the supplier to manage their costs vs. just passing them on at will gives the supplier an economic interest in suppressing their own suppliers and increasing their delivery efficiency. It pushes some of the price risks away from the individual consumers, who don't have much individual purchasing power.