Yes. They didn't just stop testing for flu when someone shows up with influenza-like illness (i.e. flu, covid). Maybe in some places where medical systems were already struggling in normal times, but not in developed nations certainly.
Indeed, most flu patients don’t even see a doctor.
So, at the outset, the flu stats are coming from a very specific category of patients: in-patients and people with great insurance who have the time and money to get tested for the flu (even though it won’t make a bit of difference what the test says as it’ll be over in a couple weeks anyway.)
This second-category may be skewing things.
The personality-type that has a ‘need’ to know whether they have the flu was instead focused on Covid. They’d have the sniffles, go through a drive-through Covid testing site, get their negative result and breathe a sigh of relief. They would NOT however make an appointment with their doctor as they perhaps would have in years past as (a) they wanted to avoid sources of Covid, and (b) the doctors were discouraging appointments but for emergencies (and flu-like symptoms plus a negative Covid test, would not, in the patient’s mind, amount to an emergency.)
I doubt this explains all of the decrease in flu-positive tests. But, perhaps some of it.