They are definitely doing this again. They have become so risk-averse in their algorithm that they have to curate "random" videos to stimulate users' needs for novelty. This video "An Old Man's Advice" with an older balding guy in reading glasses with an enormous Santa beard in the thumbnail was a recent (~2 months ago) curated YouTube promoted vid. You probably recognize it. I realized it was being promoted when I noticed a bunch of people talking about it on Twitter a few days after it popped on my homepage.

https://www.youtube.com/watch?v=JhckVlgYZJE

Here is the guy's Social Blade page where you can still see the spike in views and subscribers from late June partially scrolling off the end of his historical graphs:

https://socialblade.com/youtube/channel/UC5hWk56PCwg1D11kDgt...

Also this recent one about Fritz Haber from Veritasium is another example of a "random" curated video that got promoted to almost everyone:

https://www.youtube.com/watch?v=EvknN89JoWo

For actual novelty in YouTube I'm working on a team to build alternative YouTube recommendations. Search a channel to get a list of recommended similar channels. I like to use the list of similar channels for Y Combinator's YouTube channel as a demonstration, but you can navigate by clicking the channel icons or using the search bar on top:

https://channelgalaxy.com/id%3DUCcefcZRL2oaA_uBNeo5UOWg/