No one is restricted from "free exchange of ideas." TikTok can divest and stay in the US market just fine. It is an ownership question, not a freedom of exchange of ideas question. There is no constitutional right for a foreign entity to do unrestricted business in the United States.
US Congress likewise does not give a fuck what you think though, unless you are a US Citizen and even then you get a single vote. The US population at large has decided on this by their representative government.
It is worth noting that the Constitution itself states (interpreted as stating) that Constitutional rights only apply to US nationals/citizens (which the Constitution derives powers from) and only those residing within US sovereign jurisdiction.[1][2]
So you are correct, except this was decided at literally the most fundamental level of US governance instead of on Capitol Hill.
US Congress likewise does not give a fuck what you think though, unless you are a US Citizen and even then you get a single vote. The US population at large has decided on this by their representative government.