Given the Cambridge Analytica scandal, why wouldn't it be achievable at Facebook, let alone TikTok.

The CCP could mandate that the TikTok algorithm display certain types of political content, then further mandate that any criticism of the CCP be limited, especially discussion of the said censorship. Most users wouldn't know about it and leakers at ByteDance wouldn't be able to change that. It's not the US - they are punished in China in a way that doesn't happen in the US.