Actually gun owners were referring to their semi-auto rifles as assault rifles well before Shugarman redefined them as “AS-S-S-AULT RIFLES!”
I have several gun magazines (GUN TESTS, GUNS AND AMMO) printed well before Shugarman. Before this time, Sugarman only wanted to ban handguns. Same for Handgun Control Inc.
It was Mel Tappan who started the assault rifle demand back around 1976 with his book SURVIVAL GUNS and a Guns and Ammo column on survivalism.
Before 1976 you could not give an AR-15 away (except to me) as everyone still wanted large caliber hunting rifles.
That is likely so. Sugarman promoted the idea of confusing the public with dishonest terms to demonize that he wanted banned.