We use the term hatchery quality to explain small faults. For instance, quite a few hatchery Wyandottes have single combs. They are supposed to have rose combs. Hatcheries breed for quantity over quality. Therefore, undesirable traits pop up quite often. We also use that term to explain a bird...
They could totally be mixed if they didn't come from a hatchery. I only said PR because I assumed they came from a hatchery and that's what they resemble the most. If they are from a private seller, they are likely mixes.