China has restrictions on the content that can be made available to people within the country, and companies are required to monitor and censor the content it makes available, or else be blocked completely in the country, like Facebook and Twitter.
Rather than censoring each article that people have access to within Apple's new News app, it looks like Apple is seemly deactivating the app in China to fall in line with the censorship requirements.
A source "with direct knowledge of the situation" told The New York Times that Apple is blocking access to articles within the News app on iOS 9, which aggregates relevant news articles based on user interest and lets users save articles to read later.
The app is currently available in the US, but is also being tested in Australia and the UK right now.
Reddit user Larry Salibra noticed that the News app, which is linked to his US Apple account, was blocked when traveling to mainland China, though it still worked while in Hong Kong.
In a blog post, he explained that access to the app was based on which carrier his phone connected to, so when his phone connected to a Chinese network, the News app deactivated.
This is only happening in China, it seems, as if you travel to another country, the News app should work without any problems.