Yeah, because it didn’t fit a narrative. It didn’t have a scary name. In 2018, 80,000 people died from the flu in the United States alone. 80,000. The bulk of those deaths happened in a four month window. Sometimes hundreds or thousands of people died PER DAY. Think about that for a moment. Let that sink in. There was a weekend in 2018 that likely saw more deaths from the flu in the US alone than during this entire saga globally, which started back in November.
I don't think the Chinese government is unduly worried by narratives and scary names, but is instead inclined to be ruthlessly pragmatic.
Diseases spread. Yes, in their early phases of spread, the total devastation isn't that high.
Your statements would hold just as true for the early phases of the 1918 pandemic-- lots of people die from flu every year; still fewer have died than happened last year; etc. They're statements that are true until they're not.
There's no guarantee of catastrophe, but the potential for it is there.