I won’t guarantee but that was my first thought. Trump had their little attack dog on a leash, Trump talking tough about China, little attack dog gets poison steak, probably soon replaced by bigger dog...
It's easy to be suspicious about what happened here...especially since I suspect the Chinese intentionally released the virus to retaliate against us for not wanting to get screwed by them anymore.
Kim promised Trump a Christmas present. He hinted it would be something unpleasant if Trump didn't quit trying to bring him into the light. Seems to me Kim had some henchmen go down to Wuhan and cause an accident that would spill over to America. Xi found out; China wasn't appreciative of the collateral damage. Something unpleasant befell Kim.
The fact that they called the Chinese government for a team of doctors makes me think that China has been using NK as their missile testing scapegoat this entire time. You can bet that they will have someone else in there promptly.