There are NEVER any guarantees any particular experience will turn out to be good or turn out to be awful. So my suggestion is this. IF you decide to hear him out, agree to meet in a coffee shop or someplace. If it gets too uncomfortable for you, all you need to say is, "Look, I honestly wish you the best, but this conversation is becoming uncomfortable for me. Best of luck, please don't contact me again." And then leave. If you are talking on the phone, same thing, and then hang up.
It might actually be healing for you. I'm not pushing you to agree--that obviously is something you have to decide for yourself. I'm just saying that it doesn't have to hurt you if your head is in the right place, and you go with an open mind and a willingness to do what you need to do for yourself if it is getting too uncomfortable.