Granted,anything is possible in the movie biz,but I think it would have been a stretch to put Cicci in Part III,at least the Part III that we saw.

Mike kills his own brother,kills Hyman Roth,(who was no longer a threat to him),and kills Five Angels (who never testified). I can't believe that a guy who actually took the stand against Mike,and embarrassed him in front of the whole country would get a pass.

Maybe Michael would have been dead by then, or some other major plot twist would have been in the works,but barring that,no way,no how, does Cicci show up in III,except maybe as another Fabrizio scenario.