China says India’s ban on Chinese apps may violate WTO rules

But what they are getting at, perhaps not unreasonably, is that it looks like all these apps were banned because they are by Chinese companies, which may be discriminatory under WTO rules.

This is not what China does. China, like other countries, blocks specific websites and apps because of their contents or functionality, not because of their origin (at least if they do they tend to be smart enough to be subtle about it...)

I don't think WTO rules say anything about what websites or apps a country should allow but rather the rules are about preventing discrimination between trading partners. So my understanding is that a country is essentially free to ban an app because they don't like what they app does but they are not free to ban an app because they don't like the country it comes from.