The root DNS servers basically only tell you where the registry servers are, they don't contain records themselves. If someone censored a domain at the registry level then the root servers would be no help
But long ttls and caches would mostly break this as an approach
Better still, one can run one's own private root content DNS server. I've been doing that (in several ways) for a couple of decades. If ICANN decided to blackhole (say) www.microsoft.com. tomorrow, my DNS lookups wouldn't be affected.
To affect them, the aforementioned "court action" would have to target Verisign.