On the prog side, though known as a pick player, Chris Squire had a percussive technique where he'd hit the note a second time with the edge of his thumb.
Not exactly funkaholic, but a sideline to the development.
Nah - Proggers were post- hippies.
Certainly jazz-rock (Bruford, Stanley Clark, Weather Report, Colosseum II, Chic Corea, Alphonso Johnson) was pretty far from being hippy stuff and some of it spanned into funk & disco.
Aye - maybe omitted in the OP, but actually is at least as relevant as the guitar link there; based on that, I'd say that the funkers merely reinterpreted what already existed.
Since the guitar angle is allowed, though, it could simply be inferred to be interpretations of Flamenco guitar playing.
A sneaky attempt at a get-out:
and
...so he's not actually saying it's a Fender.
(except the title does say it and the pictures form part of the description.)