Most Helpful Guy
1. Probably holding out some hope of reconciliation.
2. Wants to end on good terms and have you remember him fondly rather than negatively.
3. Doesn't want to think of himself as a negative jerk who couldn't say thanks, I'm sorry, goodbye.
Most Helpful Girl
Most likely closure. If he wronged you then maybe guilt and compassion. Sometimes, to get attention to get back together. But a lot of people are open when that's the case.