hmm, those are definitely AI made. There's one channel I watch periodically that's hard to tell:
https://www.youtube.com/@MedievalWay
Here's a sample video.
https://www.youtube.com/watch?v=wKdKr4VONc4
I suspect the voice is AI, the thumbnails definitely are, but unsure of the rest of the content. It's really interesting and the content in the video seems legit (looked up the "forgotten vegetables" and was surprised to find that we did forgo a lot of tasty things to satisfy the machine harvesters).
Guessing it's likely a phd student with too much time on their hand.