That's definitely not "let the AI do everything unsupervised", but many short scenes generated with probably much filtering, and then manually edited together.

It's interesting how the Harry Potter fanbase was one of the first to get on the AI video trend, but not too surprising as there was already plenty of HP fanfiction, and no doubt many who wanted to have them visualised.

Here's another channel with a ton of AI parody videos: https://www.youtube.com/@NeuralDerpMusic