Yes this is true. It is a mantle BUT it's not a mantle like green lantern. T'Challa was different, from an unbroken line he is a king among kings, even Shuri, both comic and MCU version, isn't as forward thinking as T'Challa. I don't think people have realized just how huge a disservice they are doing to the franchise by trying to make it black star wars instead of focusing on an African man and what it means to be a hero, King, and a good man. We should be exploring what T'Chaka said Your a good man with a good heart, and it's hard for a good man to be king" you can't get that with Shuri, mbaku, nakia, Okoye etc. And to pretend that they can is incredibly stupid and I think they are going to see that T'CHALLA is Wakanda, as RJ put it