Does the netblock "owner" suddenly see all of its traffic dropped?
If so, this is a far more powerful takedown than simply a domain or CA takedown or revocation and takes immediate effect across the globe.
It's basically a giant "kill switch" and centralizes enormous power in the RIR's, which still have to operate according to the laws of the jurisdiction that they operate in, but span country laws.
Follow up question. What happens when a judge in (any country) issues legal notice to terminate the certificate to the RIR of a region for a netblock of an entity in another country?