Ok...I have a slightly different perspective. I think that if the kitten was meant to be dinner, it would have been killed, then carried off. I think that maybe the fox could have meant to take it in and raise it. I say this, because, my cat (who is supposed to be an inside cat) has adopted a family of foxes that live behind us. Both parents and the 5 that survived wait outside our house for the cat. We try to keep him in, but he fights all of us to get out. We can usually keep him in, except when company comes to the door.
We have even had neighbors see the cat and foxes playing. It scares me to death when he gets out and the foxes are out there, because I expect some day, they might decide he is an easier meal than what they go out hunting for.
But, as long as he helps them, watches their babies, and brings them food, I guess he is a friend??
It's crazy. They even wake me up to let him in when they are done. It is usually about 2 AM. I know that they have killed other cats in the area, though, so I don't know why they hunt with mine. I have warned all the neighbors around, though.
So, it's possible it was going to raise it. Just not likely. I know cats are an easy meal for foxes.
Shelly