That doesn't jive with the dems political ads and the Fearpers who have invested their reputations on masks being the new normal won't accept this either.
There have been numerous studies about masks and flu/virus spread over the years. Basically even the surgical and N95 don't prevent the spread and can have some harmful effects. I think they are like the blanket that Linus carried around in the cartoon—psychological help for anxiety.
Maybe CDC came out with the advice for any old mask type covering to relieve the pressure on the medical supply chain, because people weren't listening in the beginning when they told them masks don't really work, but medical people need them, so don't use them.