There are traditionally certain single-sex occasions (bridal showers or bachelor parties) where it would be OK not to invite a guest’s spouse, but a family reunion is not one of them. Normally, if a husband were not invited to a family reunion, the wife would not go, but yours is not at all a normal situation. In your particular situation, I would not press your wife to sit out the event.
I think you should contact the offending children (probably by email) and tell them that you love them, you will always love them, and while it hurt your feelings not to be invited, you understand why they didn’t invite you. Repeat if this sort of thing happens again. This will presumably come up again as your children get married, their kids are baptized, and other major life milestones come up.
As long as there isn’t some major wrong-doing on your part that you aren’t sharing and as long as the kids are reasonable human beings, I think this approach gives the best chance of a peaceful and amicable resolution. I remember a number of people in your previous thread thought that your family life might improve during the empty nester years.
