He's mostly just managing expectations. One problem starting to trouble public health professionals is the wish of vaccinated people to ditch masks even before

He's mostly just managing expectations. One problem starting to trouble public health professionals is the wish of vaccinated people to ditch masks even before enough people are vaccinated to reach herd immunity: since it is not easily visible if someone is vaccinated (and even then...) the appearance of more and more unmasked people in stores etc. could lead to a breakdown in adherence. There will come a time, in early summer for the US, late summer for most of Europe, when it'll be safe to take of the mask. Until then, it's a minor annoyance.