Um, not really. Actually, Aermacchi was a company that HD purchased for its technology. The smaller single-cylinder HD sprints, etc. were made by Aermacchi back in the day. It's probably more accurate to say that MV Agusta is based on Aermacchi design than HD design. Whereas HD did own the company, they failed to be successful with the smaller bikes and eventually ownership reverted back to Italian companies. "Directly decended" is, I think, a hyperbole.