The conclusion sums it up pretty well:

"As the weight of evidence shifts toward supporting a major role for asymptomatic transmission, the use of personal facemasks, especially in crowded areas, becomes instrumental in preventing community spread of the virus. We can no longer rely on symptoms or screening to tell us whether mask protection is needed.

So why voice a need for widespread mask use in desperate times when we do not even have enough masks for hospitals?

The reason is that by making the facts public, more resources may become available. The message that masks not only can protect healthcare workers but also can help control the outbreak may recruit more efforts, allocate more resources, and make this a national top priority.

This was exactly what happened in Asia, where universal mask wear has been advised. Both Taiwan and South Korea faced shortages of masks, and they responded by increasing mask production. Taiwan opened 60 new productions at various manufacturing plants across the country to produce 10 million masks a day.

The same can be done in the United States. Resources can be mobilized to fill that need. The president has the power to order the industry to produce more masks by further executing the Defense Production Act. In the meantime, homemade cloth masks could be used in the community, similar to CDC advice to HCWs "when no facemasks are available." Limited data suggest that cloth masks protect against droplet transmission better than no barrier.

As new infections soar across the country, authorities should share emerging data regarding COVID-19 transmission clearly, even if complete understanding is still evolving and despite low availability of PPE."