If intentional, would China shoot itself in the foot by releasing a deadly virus in its own major cities and infect potentially millions/billions?
Or would the US and its allies release a virus it knowingly funded (for plausible deniability) in a state it constantly calls its 'greatest adversary & threat' during the 2019 war games?
One of these seems more likely than the other to an objective observer since this isn't the first time the US and its allies have engaged in chemical & bio-warfare against the Chinese.
The foreign aircraft carriers and war ships surrounding the Chinese coast are perhaps yet another clue...