Your h has gone into his hole for a while. They do that. They remain silent for a long time and then one day, you'll either get a call, email or he shows up w/an excuse for something. I wouldn't be too concerned about his MIA status right now. It may be a good thing if he's actually working on himself.
I can understand why you would be a bit bothered/annoyed w/the fact that your son wasn't invited to the weddings. He's been part of the family for most of his life...but you don't know what they are thinking or feeling right now, nor do you know what your h has told them. At some point, you'll find out why he wasn't invited and whether or not your h attended.
How is the job coming along? Is it keeping you busy? What are your plans for the weekend?
Try to keep the focus on you and your son. The answers will come....
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.