Is a sibling role really a thing?

Getting married in 2 weeks. I was finalizing some of the last things on my list last night when my mom randomly just started freaking out on me. Apparently, I am disrespecting my sibling by “not including him.” The thing is, he is included from my perspective. He is invited to the wedding, he is in the pictures, he is in the front row for the ceremony next to my parents in reserved seating, and he is at the same table as my parents. We paid for staff to do cleanup and the planner is handling seating so we didn’t need an usher or to give any family jobs.

I have no idea what role she thinks he needs otherwise? Apparently he is hurt, but he didn’t tell me. Also, he and I are not close and not by my own choice. He blows up every attempt I make at a relationship. I am still contacting him 5 months after my birthday about going out to eat for it. I told him I would pay. I paid for his birthday dinner and drove to him when he said this was how we were going to handle birthdays now.

He has repeatedly done things to me for purely selfish reasons that some would call unforgivable. He was the golden child so there is no jealousy from childhood. Jealousy only started when I did better than him in college and now I’m getting married before him (his own view on that one as I’ve heard from my mom. Totally ok if someone never gets married or meets their person later in life. Not a measure of success. Also, school was him not applying himself, not lack of intelligence or financial support)

He now is not on good terms with my fiance because he shit talked him for his financial situation when he lost a job right before we met. (Fiancé is back on his feet now but it took time and he is obviously ashamed of that period and it wasn’t a character flaw that needed pointed out).

Therefore, he obviously would not be asked to be in a wedding party. Also, my fiancés siblings aren’t in the wedding party either. It’s not like there is any perception of favoritism.

I told my mom all of this but she is still upset over it. She tried to tell me he knows he has made mistakes and wants a better relationship, but there is no way that is true because I literally called last week and he wouldn’t even look at his calendar to see when we could catch up.

I feel like I have included him more than deserved and there is no “sibling role” I took from him. He is being treated the same as my fiancé’s siblings. Am I missing something?