It's a legit belief by some serious lunatic fringe elements, so I think the channel might be in serious Poe's law territory.
Most of this stuff comes from the works of Elijah Muhammad (Founder of Nation of Islam), specifically 'Yakub (Jacob): the father of mankind' where he tells how a big-headed scientist (Yakub) created white people etc.
Big Head Scientist has played their hand a few times that indicates they don't necessarily believe this stuff but they show a great fondness for the material that these videos are about. Think of it as a video encyclopedia of nutso fringe religious beliefs and cosmologies.
That's what I meant by my above comment. It seems obvious to me that the channel is making fun of this particular world view, but they've obviously spent a lot of time learning about it as well. What I wondered was whether it was fondly intended or not.
I believe that the creator of these videos is a black science-fiction nerd who grew up in an insane New Age Black Nationalist family. This is like some modern creative-play theory thing. But in the end the uncertainty is the spice, aged deeply with years of videos.