It's not the information that's banned, it's TikTok. People don't seek to ban TikTok because they fear the content, they fear the power that an enemy nation has over their citizens. It's not a free speech issue.
Imagine if a company developed a new form of paper and published many books on it. If the paper turns out to be toxic and is banned, the company can't then say "oh, no, we're being censured". It has nothing to do with the message.
The courts can look at the effect of the ban, not just the intention. If the effect is that it ends up limiting Americans' access to information (which it would, unless ByteDance gave in and sold) then a court could find it unconstitutional.
IANAL, but this is my understanding.
Same holds true of your 2nd example, if it required Americans to turn in all the books they owned printed on that paper, for example.
> it ends up limiting Americans' access to information
it is not a right to have unlimited access to any and all information.
It is only a constitutional violation (by the gov't) to _prevent_ an american citizen from any speech. It would not be a violation to legislatively ban a company, unless that company was the only place you could make speeches, and thus resulting in the outcome where there's defacto speech repression.
However, such a company ban, if it werent due a violation, would erode the trust in the US financial system. Because if the US decides they can just divest you without you violating any current known laws, it will make foreign investment in the US more difficult.
Where on earth does it say that the government cannot limit access to information? If that were true then how on earth is book censorship legal?
For that matter, how was it legal to change to digital tv broadcasts? CCP tiktok can absolutely still operate a website that wont be blocked. The medium of delivery isnt protected speech.
Imagine if a company developed a new form of paper and published many books on it. If the paper turns out to be toxic and is banned, the company can't then say "oh, no, we're being censured". It has nothing to do with the message.