Glad to hear you enjoyed your trip. Felt like I missed getting to see a friend knowing you were so close by. If you're ever back this way...
The important thing about the reunion is ... he brought it up! If it is his choice to join you then it is no longer an obligation. If he brings it up again, I would encourage it, especailly if he is putting feelers out there about you wanting him to be by your side at such an event. IMHO, it would be good for him to hear that you would like him to be there with you, but that it is his choice and he needs to do whatever he is comfortable with.
All the daily contact he is initiating is a very good sign, so I'll wrap this up the same way I started it ...