Methinks we've been here before when you were wearing a different mask - I identify you as Lobby Ludd and claim my five pounds.

£5? You'll be lucky (Jim). No mask. I've petitioned Joe Offer for a name change on several grounds but this he continues to deny me. As Flann O'Brien pointed out in the common law a man may go by any name he so chooses. But of course, his heart ne'er changes!

Blandiver / Suibhne / Sedayne / Sean etc. It really is of little consequence.

As for the other business, I doubt either Dufay or Machaut was aware of their significance to the broader Tradition of Classical Music of which they were part, much less how their work would be revered in the centuries to come, but as far as the nature of their Tradition goes, they would have been aware of their mastery of it in terms of Ars Nova even if they never themselves used the term.

Folk, alas, is a very different sort of word - as you say it prescribes rather than describes and is used by those who had feck all with the creation of the music in the first place. It's an ideal, hatched, as you say, some 9 years after Victoria came to the throne so Victorian in every sense - and utterly, and shamefully bogus besides.