There's a classic French technique called rilettes that involves cooking pig parts in stock or fat and then mincing them to a spreadable paste. It's delicious, especially with duck confit as a base instead of simmered pork, and the easiest way to make it is very similar to what Oliver did.
And of course Oliver knows that. He's had far more cooking experience than I will ever have. He knows he's bullshitting those kids. He could gross them out just as easily by showing them the pink and red bits near the wing joints ("look at all that chicken blood! ewwww!"), but he doesn't; he points to them and says "this is the expensive bit right here".
When asked what to do with the chicken carcass, the kids said "throw it out". The proper response to that statement is "no, idiot, find a way to use it" (as a parent of 2 school age children let me argue forcefully for the culinary idiocy of 8 year olds). Instead, Oliver honors the kids and their stupid, damaging assumption about how meat works. Shameful.