Fauci emails are quite telling.

Well this should put to bed the idea that the initial mask guidance was a noble lie.

I would love if the whole "noble lie" explanation for public policy was generally discarded. It is far overused, especially by people skeptical of government bureaucrats. It almost never is a correct assessment of a policy action.

Most of the time what is going on is:

a genuine gap in scientific knowledge
an actual error in scientific reasoning
a bad standard of evidence for policy in a crisis

(2) is generally minimized by the conservative, consensus-driven behavior of the experts in the government agencies, but at the cost of speed and 3).

The mask guidance error was a mix of 1) and 3).

we had very limited evidence for broad-based cloth mask wearing and we had never had a respiratory virus that had significant asymptomatic transmission
standards of evidence came into conflict with making decisions under uncertainty. Advocating cloth masks was close to a zero-cost intervention that at worst would have been mostly useless. Ideally we minimize 3) by effective policy leadership that can make the necessary calls amidst uncertainty.