Coppola has emphatically said "no" to a Godfather IV because the previous films were collaborations with Mario Puzo.

Puzo is gone and so is the possibility of a fourth film...at least as far as a Coppola-directed one, anyway.

We may indeed see a new "Godfather" film, but it will be written by someone other than Puzo, so why even bother...???

The Godfather is dead....long live The Godfather!