I'm sorry, GranandAnna, but statistically men who abuse children have the highest rate of repeat offenses of any type of offender.
That's not stereotyping. That's a fact.
Your son needs to be held accountable for what he did. He isn't safe around children - alone or otherwise. He isn't safe around your daughters. What would happen if he got together with a woman with children and then molested one of her daughters? (Not outside the realm of possibility. There are people who do this.) What if he decided to become a teacher or a nurse so he could have access to vulnerable people? (Again, there are people who do this.)
Maybe you didn't force your daughter to invite him to her wedding, but did you react negatively when she mentioned not inviting him? Did you tell her to be sure to invite him? Did you say something about this being all in the past?
The sad reality is that, depending on your son's mental state, he may not have changed. I'm not saying he is one, but many people who are sociopaths and psychopaths are capable of presenting as very charming and pleasant. It's all about their own gain. So even if he shouts to the rooftops that he's reformed, I would never trust him again. Ever.