Jethro Tull and Ian Anderson were all around me during my college years and in the early ’70s. I was never a real fan, but heard most of their work during that time.
To the OP, I say this not to detract from Ian Anderson, but more to understand where his flute technique comes from: if you haven’t already, acquaint yourself with the jazz flute of Rahsaan Roland Kirk. Anderson admitted that Kirk’s "I Talk With the Spirits" album inspired him to pick up the flute . . . it also obviously inspired him stylistically.
RRK, like every other jazz player, was inspired by those who came before him. It’s unclear to me whether he actually "invented" the sing/scat-through-the-flute technique, or just took it way higher than others had. Ironicallyl, the flute wasn’t even his "first" (favoritee) instrument--that was the tenor saxophone.
I conclude that both Anderson & RRK contributed heavily to the popularity and influence of the flute in various genres of music in the ’70s.