You're Google. Surely you can use this discovery to provide AI with clues to better alert human beings, who can then eliminate white nationalist propaganda from YouTube (or at least remove it from algorithmic serving altogether). I look at channels like the following and they practically scream conspiracism, just from the aesthetic and phraseology employed in video titles.

https://www.youtube.com/channel/UC00z8749lKJS62I5NTScwMg/videos

https://www.youtube.com/c/thejimmydoreshow/videos

And yet, there they are, selling merchandise and spreading vast amounts of disinformation. At the very least, you should be able to categorize these as conspiracy channels, perhaps employing the technique of "prebunking" you discussed in this article:

https://medium.com/jigsaw/can-inoculation-build-broad-based-resistance-to-misinformation-6c67e517e314