Taken in the way you put it, Steve, you are right. Bohemian Rhapsody by Queen is about as far from folk as you get. You are taking it out of context like others before though. The quote is

"To me, Ariana Grande is folk music. Bohemian Rhapsody is folk. I define folk as whatever you can sing in a pub – and for people to be able to join in and be as shit as you like. "

Eliza was railing against the perceived white middle class snobbery image that folk has acquired in some circles. Justified or not. Her choice of examples may have been poor but I like the boldness of "whatever you can sing in a pub". Not sure if I entirely agree but "join in and be as shit as you like" is something that is often missing in some circles.