I suspect this circling could be some sort of defense mechanism. It is quite common for other bird types join together to attack hawks, and they could be checking the cat out to see if it is worthy of being attacked.
I once watched a feral cat stalk a rabbit, both about the same size. A couple hours later I found the cat having lunch on the rabbit.
For sure a cat can and will easily kill a baby turkey.
My experience in the woods is that a cat will attack just about anything. If they can sink their teeth into a prey and mobilize it, it’s done.
Around here, Montana, baby turkeys are food for young mountain lions.