For a good while, around China and other parts of the world, they would definitely have attributed the symptoms to the ill as flu and the cause of death for the dead as pneumonia/respiratory failure. This goes back further in the Winter, for sure.
We'll never know I guess. It wasn't pleasant for sure. In my lifetime I've never seen a worldwide situation like this with countries in lockdown. I do believe there is a lot more to this than meets the eye that is being kept quiet, but you can drive yourself nuts reading all the conspiracy theories.