If North Korea had 0-day browsers exploits, they wouldn't be using them on cooks.org.kp
ublock only blocks known trackers or obvious ones, so it doesn't do anything to protect against potential browser exploits Kim could be running.
That being said, I doubt North Korea is sitting on too many unknown browser exploits.
I'm not fucking kidding, but after I've visited cooks.org.kp my internet is slow and I've some packet loss and timeout...but nothing weird on little snitch