Cloudflare does not have any IPv4 blocks in North Korea. Geolocation databases use RIPE as the primary source and then make estimates using various tools.

Interestingly, according to RIPE, North Korea has only assigned one IPv4 block (see https://github.com/analogic/ipgeo/blob/master/by-country/KP), whereas Antarctica has none.

Cloudflare is a big player and can get the geoip providers to do basically whatever they want.