FR is directly accessible at http://188.8.131.52
The domain name merely maps to that address.
Which means you can still get to it if they block or remove the record from the DNS resources, but that doesn’t mean IPs can’t be blocked. Still I think the later would require ISP cooperation and would be much more drastic a move.
ISPs blocking would be a severe action, probably violating “common carrier” laws. They’d be sued, customers would switch providers, and (acting as originally designed) internet would largely route around blockage. Worst case, there’d be a market for new non-censoring ISPs & backbones; some viable & interesting tech is waiting for the opportunity.