Not only TikTok. For example the Bitcoin network can not be controlled so a transaction from an American citizen could potentially go to a citizen of a country that's "a menace" for the USA (definition of enemy and menace is discretionary, the used language seems fine tuned to allow scope enlargement at will without judiciary supervision). Since that's not controllable, we find it potentially possible that operators might be required to block "the Bitcoin network".
What's worse, according to a preliminary interpretation of the text, if in some way (difficult but personal and house search, pre-selected through the usual monitoring performed by USA ISPs, can help...) it can be proved that a USA citizen has used some tool like Tor or VPN to access any of the blocked network / services etc., that citizen will be prosecuted: civil liability up to a million of dollars, and criminal behavior subjected to up to 20 years in jail - which, if we're not mistaken, is worse than in China, Russia, and various countries controlled by human rights hostile regimes.
Kind regards