Apple stores aren't getting any shipments right now. Even if they were, those stores are closed and Apple isn't going to open them to sell a few face masks to consumers. By the time Apple stores open, even fewer people will want face masks. (And Apple won't want them on their shelves regardless)

Apple's distribution network is built around selling consumer electronics, not medical supplies.

This isn't remotely the sort of product Apple would manufacture and sell. It's not worth the time and effort to design retail packaging for it.