I'm far away from my magazine archive, so somebody else will have to verify (or disprove) this.
I recall an interview with Duclos-LaSalle in Winning shortly after his second P-R win, in which he said that riding the sprung forks was a nod to one of LeMond's many sponsors, and that he rode with the 'boing' locked out.
That might explain why they disappeared after two years. Legislation may have had nothing to do with it
Marie Autrey Water Island, US VIrgin Islands, where only an optimist goes in hurricane season