I feel for your brother: it definitely sounds like he is in an abusive relationship (says wife gets "violent" when they argue, cuts off his sister to please her, won't drive to pick up his parents on her say-so, has an e-mail address he keeps secret from her
..)
IMO, being there for him and helping him if you can to shed his denial about his wife's treatment of him trumps the feelings of hurt you have regarding how he cut you from his life. But that is of course your call to make.
I'm not an expert in help for battered men, and the people who love them, but it is out there, as a quick Google search shows.
It may not be possible to open his eyes, mind. My DF has been abused by my mother for 40 years, and is so deep in denial and dependent on her that I don't think anything will get through to him to help him help himself. But it is heartbreaking to watch how her put-downs, contempt and control have just broken him.
The relationship model that their marriage is going to give their new baby will be damaging to the child, too. These issues will get passed on to the next generation. If your brother's eyes can be opened, then he can save himself AND his child from the soul-sucking effects of abuse in the home.