This has to be a state actor thing, nobody else has the resources to deploy such a long lasting and changing content farm. Some psyops to fuck future generations of adults up?
According to the article, the videos feature nudity and possibly sexual harassment. Sexual harassment is unfortunately a fact of life, and it’s probably better that children recognise it, and see it condemned in the media they watch, than not know what it is at all. And you would have to be a puritan to think that children seeing naked people is somehow so terrible.
If you bothered reading the very short article, it would be very clear that people are deliberately getting children subscribers than replacing the flow of new content with attempts to brainwash them or expose them to obscenity.