"When breeding and hatching Turken only about 90% come naked necked and 10% come with feathers on their neck. We only ship you the naked neck chicks, however they will also have offspring if bred pure that will be 10% feather necked." from the website.
https://www.cacklehatchery.com/turkens-naked-necks.html
Ok, now I understand what you are saying. I was getting some of the fully feathered neck chick's before when I was still using the white NN rooster over the hen's. I'm using a different roo now, and the chick's that hatched from my last batch from my flock all had the naked neck's, and none had the fully feathered necks. Now I just need to work toward's the cleaner looking neck's on future chick's.
Things will change as it grows up. The Nn can look like they have bibs, bowties, or be naked clear down the front making them look like they're wearing a v neck shirt. It all depends on genes.