Well, not necessarily. You see, Sawchuk was indeed very much a new style of goaltender but given the tendencies he had to stay upright, he was actually a hybrid goaltender, not a butterfly.
It depends on who you talk to about this subject, but a lot of folks consider Glenn Hall as the first to drop to his knees to block shots. Sawchuk and Jacques Plante were primarily stand up goalies who dabbled with the butterfly...but after Hall started it. Roger Crozier and Tony Esposito popularzied it further...well before Roy showed up in the '80's.