no , they probably didnt deliberately exclude them,but more likely didnt think that they had anything worthwhile to contribute,that decisions such as were made, were better made by the EFDSS or their representatives,Than by the people from whom the songs were collected.
I am sure If Douglas Kennedy were alive today he would think and act differently,he and all the other delegates were products of their times,some of them still tinged with British Imperialist notions, and all of them affected by class attitudes that were prevalent at the time.