Earlier quoted context omitted.
It wouldn’t matter. To make it effective the FCC would likely ask all the ISPs and Carriers to block TikTok IPs at the network level.
Have US ISPs ever been asked/told to block IPs (or even DNS) before? I don't think it's something the FCC could do, especially since they've abdicated most of their authority over the internet to the FTC. Even still, I doubt they have the authority to do it or the means to impose penalties for noncompliance. Even if they could - what is a TikTok IP? I'm confident their US endpoints are AWS or Google Cloud - good luck…
Also ISPs and Mobile Carriers have their own blocking and network redirection methods, like url filtering with transparent proxies, that are used to re-lane traffic based on bandwidth usage. a.k.a putting Netflix on the slow lane