Effectively "Sailboarding" (ie a small boat on which you stand and steer with the rig) was "killed off".(The word I mean)
Windsurfing (A large surf board with a sail which you steer with your feet) was deemed "The Sport".
Semantic note : Serenity turning is actually done by foot steering (opposite to funboarding foot-steering though), not much by sail steering (except tacking/jibing as per funboarding). Serenity is "Windsurfing" by your definition and has nothing in common with the original "Sailboarding" Windsurfer barge, especially in ultralight winds...