I took a quick look at this puff. It seems to me that the people they are referring to are singer / songwriters and singers that sometimes sing folk songs. I don't see many (any?) folk.

If you are looking for an organization that really appreciates the Folk Music of the USA and promotes the real thing I suggest you go to the Field Recorders' Collective. They have put out numerous recordings over the years and have just launched a 15 album series with fantastic notes, research and photographs free to download. I have just recently received the Preview album and am amazed.

Check out fieldrecorder.org/nat   These people are serious. You will be amazed too.