Turkey toms will let you know there is an official vehicle with a siren on, approaching, long before you hear it. They are loud about anything unusual, letting you know to come out and take care of whatever it is. They tend to hold their fire for use against other toms, not preds.
Turkey hens are excellent sentinels for warning flocks of aerial threats (two or three of them standing together with their good eyes up - whining to one another in assessment - hawks trigger immediate pred call/ any plane that isn't a standard commercial jet? - lots of whining). Turkey hens are pred buffet if allowed to nest in unprotected areas.
Occasionally a tom will inadvertently kill a chicken hen/duck trying to breed it. Guess you could eat both the tom and his victim...
I suppose the size factor might intimidate most domestic cats and they will definitely go after snakes of any length (hens in particular) but they are not going to save any flock from determined predators on four legs.
This applies to heritage varieties - Broad Breasted turks? not so much.