Per comments from Holmes himself, the idea for the name had nothing to do with Tolkien’s works, nor the movie. It was instead to denote royalty and lordship. I have seen nothing in any of the reporting to indicate that this had to do with anything other than the name of the food truck. The truck wasn’t going to be themed after the books or films. There wasn’t going to be any trade dress or vehicle wraps harkening back to those works of fiction. There wasn’t to be a flavor of chicken called “One wing to rule them all.”
So trademark holders being douchebags as usual. The Lord of the Rings isn’t associated with chicken wings in anyway so how could consumers be confused?