For what it's worth, Cicci returned as a character in an earlier draft of the screenplay of Part III. He was only replaced by Joey Zasa when actor Joe Spinell died. So according to Coppola and Puzo, Cicci was apparantly forgiven and even promoted after his betrayal, and would turn against Michael yet again in Part III. They probably didn't given much thought to it, or perhaps they intended to replace him anyway in a newer draft.