I don't see that adaptations of the 1954 idea do not allow things to expand. Shoals of Herring is known by just about everyone in folk. Likewise for a tune, who doesn't know Caliope House? Some things just fit in. Others may take more time to get there. Personally, these days, I find the "I've written something with 'meaningful words', therefore it is a 'folk song'" harder to accept.

Please note that I'm not suggesting that the "new song with 'meaningful words'" may not be appropriate for a folk club.