They already have a mobile web interface, that anyone can crate a shortcut to. It'll work fine as-is, with or without a 'PWA' buzzword.
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.
How exactly would the do this block? At the ISP level? I don't _think_ the US Government has ever done that before, a block on that level would be pretty unprecedented and might be more then they are willing to do.