(cloth masks) do not in themselves predict a lower spread of C19. The medrxiv is not associated with Yale University as far as I could find.
The people who publish this stuff are graduates of Yale - maybe.
No conclusions.
CDC says, any barrier (a cloth mask) helps stop the droplets going from one person to the next.
The mistake here is the belief that a mask stops you from getting the virus. It stops you from spreading the virus
is what they do. Also social distancing is the other key.
But yes, one of the talking heads on TV noted, that mask wearing is associated with the drop in cases.
This has been noted from the outset over a year ago.
Wear a mask.
Link: https://www.mayoclinic.org/diseases-conditions/coronavirus/in-depth/coronavirus-mask/art-20485449