Well, even if DiFronzo isn't the "boss" anymore, it's because he voluntarily stepped down. At least according to sources like the Chicago Crime Commission, he was the boss.

So who do you think is the "boss" now? Who is the boss of the south side crew?

CW is the succession is: Aiuppa, Feriola, Carlisi DiFronzo.

Not saying it's right, that's just what I understood.