When people use the word 'flu' they are often referring to the illness and not the virus. That is, there are several viruses that can cause 'flu-like' symptoms besides the influenza virus.
Without definitive evidence that the covid-19 is 'new', it is reasonable for people to wonder if some cases of the illness commonly referred to as 'flu' for the past 1000 years may actually have been caused by covid-19. In short, are we absolutely sure that there is some statistically signicant increase in the number of flu-like illnesses in the past three months?
BTW, covid-19 is the disease (same as the flu). The virus is named SARS-Cov-2.
I know that's what most think. But, what is the evidence? If one were to test samples from 'flu' patients from the 1980s, how do we know one wouldn't find SARS-Cov-2 in some samples? Has anyone done this?
Merely finding similarities between the bat version and human version doesn't tell us anything about how long it's been in the human population. (For that matter, it doesn't tell us if the virus went from bat to human or human to bat... there are for more bats exposed to sources of human viruses than the other way around, you know...)
That's separate from the concerns of too many people getting sick quickly, overwhelming our health system, so people who otherwise would get medical attention die.