No, but there's no harm in it either, and some potential benefit in case it takes a few days for the federal government to organize a response.
We all assume the government is going to make sure the food supply is maintained, but everyone is also buying some extra food just in case there's a temporary gap.
We don't need to choose just one way of preparing for the unknown.
Also, I was just saying the general public might purchase a few of these masks for themselves for their own use, not that hospitals might rely on the public for supplies.