From TikToks perspective, they may want the hard decouple so their users pressure their representatives. If they make a pwa or some other means to subvert the ban available it could undermine peoples desire to act.
If a government really wanted to block internet access to a service provider, they'd block access to their servers, on all ports. The workaround would be a VPN, not a web interface.
The US has this strange banning-but-not-really, because really banning it would be prohibited by the constitution's first amendment.