I think a major problem is that "we don't recommend masks" too easily gets interpreted as "we recommend no masks", and we need new clear language to say the former (no position on masks) with no risk of misinterpretation (position against masks).
Edit: I misremembered the original advice. CDC specifically said masks were unnecessary. Obviously they didn't have the evidence to make that kind of assertion.
IDK about the WHO & CDC, but “the leading spokesperson on matters of public health in the federal government of the United States” (according to Wikipedia) did not have “no position on masks”. I’d quote him here, but his position was emphatic enough to technically break HN’s guidelines: https://nitter.net/Surgeon_General/status/123372578528393216...
I would take a step back from partisan politics for this issue, something people have a very tough time with even in the best of times. We should criticize all institutions when they're wrong on questions of public health.
You are right. CDC said in March "You do not need to wear a facemask unless you are caring for someone who is sick (and they are not able to wear a facemask)".
Edit: I misremembered the original advice. CDC specifically said masks were unnecessary. Obviously they didn't have the evidence to make that kind of assertion.