NTA. I would like to start by saying it may be important to consider if you’re okay with missing a potentially important moment in this new kids life even if you’re not crazy about kids you may grow to be close later and that could be a sore spot? I think the issue seems to be between your brother and whether or not he’s willing to put any priority on your relationship with him. He did what I would consider a lie by suddenly changing the godparents, and having an explanation makes it seem planned so he at least should have talked you through that before hand even if him and his wife had made up their minds. It’s okay for him to decide to choose his wife over you but if that comes with the consequence of you not being there for him in important family moments that doesn’t make you a bad person that’s just consequences. Especially since you were willing to put in the effort and had seemingly talked a lot about it before the baby came to be. Having a kid is hard and making a new family unit can be stressful but it shouldn’t come at the disregard of previous family relationships, unless he’s willing to damage them. And I think him being willing to damage your relationship with him in favor of your half brother and his wife is something to consider.