They probably saw the Russian culture war brain rot play out with American youth and decided to have a circuit breaker.
Behind the Bastards has an episode about how YouTube went right wing to create site engagement and an anger economy, and an episode about Facebook doing thr same for boomers.
Some governments are looking into limiting those influences.
EDIT: oh yeah, China might also be protecting children from hearing about the periodic stabbing attacks that happen at schools over there. Forgot about those.