It’s his brother. I don’t know what kind of relationship he has with Charles and William but he seems very involved with the rest of the family. He and Fergie were extremely involved with the Queen and the others.
It is his brother but I just can't see Charles wanting him there. This is a clean slate, a new reign and I think Charles doesn't want to rock the boat with the public if he can possibly avoid it. Plus I have never had the impression that he and Andrew are close either, quite the opposite I think.