1.) It's pointless, TikTok is officially banned in US. Even if trump decides to find a US buyer for it, it will go under strict ownership investigation. So there's no way Chinese government has any influence anymore.
2.) This means that any future Chinese apps that get popular will get banned, and no need to go through any court challenges since there's precedent and law
3.) A lot of people already left TikTok and will not come back - why would they when they know the app could be gone at any minute? The traffic from the original TikTok will just keep getting split and syphoned, until the magnificent seven claims most of it
Edit: I think all it needs is a link from a friend to some TikTok content and they are back in.
Trying to argue about legality is unlikely to hold much sway given how other legal issues ended.