Disposition is just one of the parameters that reputable breeders select for in their breeding stock.Turkeys can attack humans, no matter who imprinted on them. They are a lot like roosters in that regard. I think you can avoid it by only breeding docile turkeys, but I don't know if any breeders select for nice turkeys.
I also do not imprint my chickens. None of my roosters have ever been human aggressive.
You do realize that this is learned behavior due to years if not decades of irresponsible interaction between the people and the turkeys. First a few turkeys show up. The people are thrilled and start feeding them and doing their best to make the turkeys comfortable with them. Once the turkey population starts exploding to lack of any predator control and have become accustomed to the free hand outs their leavings are not appreciated.I have family on the east coast and their neighborhood is terrorized by wild turkeys who will attack people. The wild turkeys were not imprinted on humans as poults.
People start trying to chase them away while others keep feeding sending conflicting messages. Then the turkeys also get to deal with the people who are terrified of them and start running from them. Once the flock has learned the bad behavior it quickly teaches all the new poults the same behavior.