It happened in the comics but it made sense, Shurri was trained as a warrior since being a child, in the films she is just a geek and looks frail as fuck. I think they should do a filler film, a prequel with T'Chaka as the protagonist, in his prime and facing Namor and just maybe have that forced "Disney feels" ending with T'Challa's birth also as a way of saying goodbye to that character but I'm against the idea of retiring T'Challa, he's the main character of the mythos, without him there's no point.
Besides they ended up telling every Black Panther story there is to tell with the first film, all his main baddies were present and only one is alive now, T'Challa is in peace with the passing of his father, he's king, there's vibranium etc etc. It's like they knew Boseman had cancer and that's another reason it was such a long ass film with all the Panther mythos in there.