Do I, as potential audience, have any right to expect anything remotely resembling the accepted definition of folk song which my, and just about everbody I was involved with's understanding of the term is based on?
No, you do not because other people's understanding is different.

That sentence wasn't about the meaning of words. He was saying, could he expect to hear that music performed anywhere? And you know perfectly well what kind of music he had in mind.

And he's perfectly correct that it isn't as easy as it was 20 years ago, though not as difficult as he makes out.