Yeah, right. Chine gave NK the bomb (or looked the other way all these years)
Not at all. Quite the opposite is true. A nuke NK has never been in China's interest.
Don't make the mistake of thinking that the region is monolithic. Regional animosities in that part of the world might just astound you. They may both call themselves communist. But that's where all the similarities end.
Another point here is the use of a peculiar word. I don't know what it translates to in Mandarin, but the Chinese choose their admonishments carefully.
"Brazen" indicates that in private the Chinese might have been trying to coerce Kim to cool down. Like an unruly child, Kim took the "brazen" step of ignoring Chinese "recommendations". Not a good move on his part.
The Chinese are masters at choosing their words.