I find this so confusing. Rupert Murdoch and Elon Musk are foreigners who are both demonstrably influencing American politics through media they control. What makes Tiktok different?
Tesla is headquartered and has most operations based in the US. Murdoch's ventures are similar AFAIK.
Given how much surveillance modern vehicles do I wouldn't be surprised if imports start being subjected to additional scrutiny at some point. But at least most vehicles can't be used to subtly and intentionally manipulate the owner's perception of the world so I guess the stakes are a bit lower.
Here's a piece of history from 1985 that talks about it: https://archive.ph/HlHrx
But really, what makes Tiktok different is China.