TikTok's biggest short term threat is probably the CCP, which has been increasingly taking a hardline approach w/ their own tech companies (think Ant Financial, JD etc).
The CCP is taking a hardline with companies domestically. There's a huge push to stop corrupting the youth, treat data responsibly, etc.
The CCP gives 0 shits what those companies do to the rest of the world, and are probably thrilled if TikTok causes political and social chaos in the US.