> There is a law that only U.S. citizens can own TV stations.

The communications act did not ban already-existing networks, and it did not ban specific providers. The tiktok ban is targeted specifically against one social media that the government does not like[1], with a thin veneer of "security concern" that people might specifically choose to share their contact list and that one of those contacts may be in a sensitive position.

[1] I don't even really think it's about the government not liking it! They thought they could get cheap support by drumming up anti-chinese sentiment and they ran with it. It's the most pathetic kind of politicking.