I think the idea is to continue the same restrictions you’d see in other community settings until such time as herd immunity has locally squashed the virus.

Vaccines aren’t 100% effective - it decreases your likelihood from exposure 70-90%. If the population was masked previously they were already 70-90% more protected than without any mask/social distancing. The two together means you’re 95+% more protected than with no precautions and no vaccine.

Now remove the masks and the social distancing from the equation. You’ve almost completely wiped out the advantage the vaccine has given you. You’re right back where you were pre-vaccine.

But that’s only the protection from exposure side of the equation. There’s also the likelihood of exposure side of the equation. If we achieve here immunity we will be 90% less likely to be exposed. At that point the difference between masks vs no masks is 1-2% better protection. That’s when they come off and we all go back to whatever normal is now called.

The former should naturally follow the latter, of course, but why set criteria based on something that should happen rather than what is happening?

I suspect that by fall, the mask requirement will be able to be dropped based on greatly reduced spread.

Ongoing surveillance testing seems prudent for awhile.