If we're talking about people who don't have accounts or don't view Facebook (which presumably people with deactivated accounts don't), then they're not looking at the News Feed (or whatever the TikTok equivalent is) and can't be influenced that way.
And practically speaking, there's very little China can do to an "average" American citizen based on browsing habits and stuff like that. Now if a person ever goes to China, then I agree they'd have a problem, but most Americans don't.
Meanwhile, there are plenty of ways for the US government to (legally) use the data Facebook has collected against its citizens.
And you can't even claim it's inaccessible and hidden away in Google and Facebook data centers, because there's no transparency into who has access to it, so we really don't know.