What a strange comment. That's like saying Tim Cook sanctions Chinese factory worker abuses by visiting China.
Any trip to North Korea has to be approved by the regime. It doesn't make it a state-sponsored trip.
From the American point of view, it was a private trip arranged by a former New Mexico Governor, to both express continued interest in an American being held by North Korea, and to promote the idea of opening up the internet.
As we all know, information flow is one of the first steps that help to open up a restricted country. NK is an extreme example, with supposedly no more than 1,000 computers (used by the elite) in the entire country that are allowed to access the outside internet.
Not long after their visit, NK opened up mobile internet access to foreign visitors, which is a good thing.
Clearly, otherwise it would've been there.
Obviously something else delayed it. As I said, there could've been a fear of reprisals against Apple stores, or of network attacks on iTunes.
I agree, I don't think China was a factor. (Even though China still subsidizes North Korea, it's obvious they also think NK can be a destabilizing wildcard. That's why China wants NK to agree to denuclearization of the peninsula.)