The story might have made more sense if the writers/editors at kentucky.com knew the difference between a copyright and a trademark; they are VERY different things.
A copyright is designed to protect the copyright holder. And, regardless of the actual usage, a trademark is DESIGNED to protect the consumer.
I suspect that everybody here has been receiving links purportedly sent by people they know, actually leading to spam sites or even worse. And many of you, the first time you saw one, may have clicked on the link, thinking it was from a friend or relative. That is what trademark violation is; taking the name of a product that someone else has put their reputation behind, and pretending that it is theirs, and not yours. And who gets hurt immediately? The person who plonked down the money, thinking that it was your product, and got something different instead. If the product is indeed inferior, you also get hurt, but more indirectly, in the loss of reputation.
However, because the trademark is there to protect the consumer, the trademark holder, unlike a copyright or patent holder, has additional responsibilities. They are required to keep using the trademark, and they are required to vigorously defend it. Consider the software concept of "abandonware". Computer programs that have not been available for years are still under copyright. And the copyright owners usually look the other way. But, sometimes, they reissue the products (like those $10 thingies you hook up to the TV playing all the old video console games). And they can and do stop people from distributing these games, even after years of neglect.
If a trademark holder does not actively stop others from using the trademark, they are considered to have abandoned it, and the label becomes a "generic" term, where nobody can use it as a trademark. Mind you, they don't have to try to collect lots of money in damages; agreeing to a "cease and desist" satisfies the defense requirement.
A recipe can be patented (or the exact wording can be copyrighted), but only for 17 years. But a trademark is as long as it is kept active. So, there is no problem with restaurants, or people for that matter, using the recipe for the Derby Pie product. But if Kern doesn't sue people who call their product "Derby Pie", they will lose the trademark. And there is plenty of precedent where if a product is called by the trademark by the providers, even if it is only verbally, that IS a violation.