There was no new data to support a change in guidance on cloth masks. The argument made is that omicron was the factor which warranted the updated guidance on cloth masks. There is no data to support the idea that cloth masks were suddenly uniquely unsuited as countermeasures.

Edit: The CDC is so infuriating. They still link the term “masks” to this page, that shows a picture of some useless facial decorations on the same page discussing N95 respirators. If we had a sane CDC, all imagery and messaging would be around N95s. They have killed thousands of people with the implicit lie strewn across all their messaging that there some kind of meaningful equivalency to be made between all masks. The unqualified term “mask” should have been struck from the messaging two years ago. https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-si...