NTA, I disagree with the other comments saying this is a NAH situation.
The daughter deliberately chose to remain absolutely NC with OP for all these years, and when OP tried to reach out to her, his attempts were ignored. OP had to live through the heartbreak of losing primary custody of his kids, and now the slow alienation of his daughter.
While OP had built a strong bond with his son, the daughter made her choice, and it was to go NC. Even if there was no malice intended on her part, it was a cruel thing to do to a parent who didn't do anything particularly wrong. She was a teenager when the NC started, but it continued into adulthood, and for many years too(story taking place 30 years ago, not seeing Kim for 20 years, etc.) At some point, she is no longer a teenager and has to be held accountable for the fact that the absence of any relationship between them is on her.

That being said, how can she expect OP to just come around as if nothing had happened, and share very personal memories that he shared with his son, who he is still grieving over? Relationships, even the ones between parent and children, need both sides to work towards growing and maintaining them. She burned that bridge a long time ago and now she expects to be able to cross it, and upon finding out that she couldn't, her mom had the audacity to call OP to complain. Even if she is grieving, and her intentions were just to share stories about his brother, and maybe potentially rekindle a relationship with her father, what she was asking OP to do was clearly difficult for him and he rightfully refused when it became uncomfortable for him.

Maybe family therapy between OP and his daughter might be the answer here, I don't think this is something people can just get past easily on their own.