Flu deaths each year vary widely but are nowhere near 40,000.

Deaths attributed to the ’flu have varied between 11,875 and 28,330 per winter season

https://facts4eu.org/news/2020_apr_covid_and_flu

The number of excess deaths from March 21st until Jan.15th, over the same period 2019-2120, is about 80,000.

https://fingertips.phe.org.uk/static-reports/mortality-surveillance/excess-mortality-in-england-late...

Given the drive to vaccinate against flu and the precautions in place against covid, a drop in flu numbers is hardly surprisng.