I believe Nicodemo is Frank's oldest son, who is technically the family's patriarch. I'm not sure, but I vaguegly remember reading somewhere that Francisco was out of the game. Perhaps this Michel is now representing the group since he was named along with Domenico Violi as attending that meeting.
I think, if true, a clash between the Rizzutos and Cotronis had to happen at some point. I'd say it was even inevitable given the history.
"It was between the brothers Kay -- I had nothing to do with it."