* The Parma ruling was not that the government was allowed to detain him, it is that the police could not be punished for their mistake. The entire thing is predicated on the police having made a mistake, i.e. this case shows they cannot jail you for speech.
* Cohen vs Barr: the courts ruled that the government overstepped, i.e. the First Amendment offered the protection I am claiming it does, and you are wrong
* TikTok ban mechanics: The government will fine app stores and web hosts that serve TikTok. This is a clear violation of First Amendment rights. It is not a condition of the app store ToS's by any weird mechanism like the one you describe.
* We're not talking about preventing foreign speech. We're talking about preventing American companies from serving the websites, applications, and content they wish to serve.