As a general observation it seems folk is more split between trad and progressive on a formal level ("the 1954 definition") than other music but not on a practical one - most people having a reasonable expectation of what they'll see/hear under the folk banner.

More a misuse of traditional (Dylan!?!) than folk perhaps. It does seem curious the music 'of the people' even people who no longer exist requires precise boundaries set from outside committees of experts.