The question is not what a flock is called; the question is do they flock. They do flock. Also groups of turkeys in the wild are called groups, flocks, dules, and broods. The term rafter is used when referring to large groups of domesticated turkeys (poultry).
I saw the first wild turkey ever near my garden last autumn. It was a 'jake' (teenage turkey) I once saw 50 turkeys in the country while driving. They flew away as my car approached them. I guess they were chicken.