My grandparents knew some of these songs. I was a baby the first and only time I heard them.
The cruel irony to the so-called folk revival is that most of those whose legacy was being preserved were more interested in survival and maintaining material wealth, so they adopted urbanization and the dominant cultures of New York and LA, while these cities and multicultural centers is where these traditional rural forms ended up. (For me, Bob Dylan is a symbol of this process.) The baby-boomers in the countryside, at least my parents, were won over by rock music from the cities, transmitted on AM stations and through television.
I could pretend to have inherited these traditional forms from my grandparents, but mimetically it's not true. My parents had virtually no part in it and in fact didn't like it. They had personal problems with their parents; from what I understand, the cultural generation gap between the baby boomers and their parents was enormous. So it was not transmitted to me orally.
This is another thing that without the internet I may not have learned about. Luckily my parents interested me in music at an early age and as they grow older they honor their parents more, and are interested in rediscovering traditional music.