I have some questions for you, Evan.
I do not challenge that the image has quite a bit of fruit present. I would like to see more closeups of this plant's parts, and then some general images of the whole plant, its growing conditions and its associates.
I would posit that what you air-layered is not what you thought you air-layered - at least not all of it.
I think I understand you to say that you know of an Ilex x meserveae 'Blue Prince' from which you air-layered several stems, severed them once they were rooted, planted them, watched them grow, and then determined that one propagule has begun to produce fruit. Tell me if any part of that is false.
Do you have pictures of these propagated plants in bloom during any part of their life with you? I would want to see that there were all male flowers on the plants, and that now there are female flowers forming which then set the fruit.
I can theorize a couple ways to arrive at the current condition, but I'd like to hear from you first.
I don't know of an instance where a species of holly like this "changed" sex. I am aware of dioecious species - those that have either male flowers on an individual plant, or female flowers on an individual plant (Ginkgo biloba, for example) - which at some point in their maturity produce the opposite sex of flower on part of the plant, creating an opportunity to pollinate and produce fruit on the same plant. That is not the same as what you may be suggesting is going on with the plant in question.