Not exactly unprovoked, in the eyes of the heathen Chinee. We have been 'waging war' against them for a while now, in the form of trade, tariffs, and getting our business out of China and bringing it home.
Not to mention standing in the way of their expansionism (Hong Kong, Taiwan, China sea, and other parts of the world). Also messing with their NK.
This flu attack and subsequent hoax is China working in conjunction with the derp state, which at the moment, China is a part of.
Ya just gotta pay attention to figger this stuff out.