It was an unknown disease - trends or not, the alarm should have been raised from the beginning. There are no excuses for this. The Chinese authorities covered it up until late January.
With respect... that's the point. It was an unknown disease. It isn't as if, when someone dies, they instantly identify all new pathogens their body, or something. That's not how the science works.
To start with it wasn't even recognized as a new disease. In the first case... some person with a cold or flu got pneumonia and died. That happens with normal colds of flu. It isn't unusual. You need several cases before anyone has even a chance to notice that they are similar or related, or form a trend. Then you have to find how they are related. Then you look at that trend, and it then takes time to isolate the source. And none of this goes as quickly as on police or medical drama shows on TV.
The idea that, off the first case, they'd suddenly announce to the world that there's a new deadly microbe is, in the phraseology of science, "not even wrong".