The word breed does not mean it has to breed true lol.
A breed is a specific group of domestic animals having homogeneous appearance (phenotype), homogeneous behavior, and/or other characteristics that distinguish it from other organisms of the same species.
Heritage breed or hatchery? Just about all hatchery birds lay the same rate and lay far better than most heritage birds. And a red sexlink is a breed. Being a hybrid doesnt mean its not a breed. My dog is a puggle, half pug and half beagle. Puggle is still its breed. But I vote dominique as well...