As much as I hate it banning Tiktok would allow for banning any other company for NationalSecurity™ and you know how that goes. Cough cough @Snowden cough cough
They can only ban foreign owned companies. And currently only from a small list of adversarial countries. Notably, China, Russia, Iran, N Korea. They would have to make another law to add more countries. Apps that they can ban with this law besides tictok would be like , WeChat (which I actually use) , Temu, DiDi, maybe Yandex apps.