Back then, after the Battle of Hogwarts, everything happened much too quickly. I didn't get a chance to exchange another word with him, let alone find out afterwards if he was still alive. He could very well have been dead. The Death Eaters wouldn't have hesitated in that respect if they had caught him and found that he had no ambitions to join them. I only learned much later where he ended up, when he was sighted during an attack on what was then still a makeshift Resistance camp – on the enemy's side. Since then he has been ostracized in our circles and the name Zabini has been little more than a swear word.