The Bigger Story
That’s surely a factor, but I don’t know how large it is.
One possibility is that as the baby boomers retire this temporarily lowers the average age of someone in Medicare.
An incredible amount of health expenditure comes near the end of life which tends not to come at age 65, and usually with chronic conditions that take longer and are more expensive then COVID.
You need to look at it relative to total personal consumption expenditures. Back in 2007 I found that food plus health care expenditures as a share of total PCE had not changed much over time, though the share of food has declined dramatically.