The Rosatos were involved in a public shootout with police. Hard to imagine they are still on the loose.
I always assumed that they were swept up along with Cicci and Frankie but, you're right, that was left unresolved.
When I first saw GF III, I immediately recognised Carmine Caridi in the Hotel assassination scene. He's the guy who gets (somewhat ironically) killed going back for his "lucky coat." So I naturally assumed that he was playing Carmine Rosato again, implying that he had made peace with Michael. It was only some time later that I discovered that he was playing an entirely different character, Albert Volpe.
An unnecessarily confusing bit of casting.
