Hatchery Golden Comets, should be that cross or a similar one, but hatcheries have a way of adding in anything that is convenient for them, grabbing fast feather cockeral lines from a breed they already have that is similar in type, etc, or slow feathering or better rate of lay, anything to increase PRODUCTION and sorting ease. So yes, they're mixes. To what extent, depends on the source.
Hatcheries will do that to any breed, even supposed purebred breeds. Most people who get hatchery delawares discover that the hatchery added columbian rock, or some other breed to boost production, and the result almost kinda looks like a Delaware so they sell it that way.