I know that I can't be the first or only person to think that Letitia Wright is SHURI. I am pretty sure that I saw that speculation here awhile ago. As for Phylicia Rashad...hmmm. Who could she be? She has to be somebody's mother. I really have no idea. Perhaps an original character that Coogler created? What about the school matron of The Midnight Angels? The one overseeing Ayo and ole gurl during World of Wakanda?
Letitia Wright could also be Monica Lynne. I really don't want Monica to be in this story, but...it's almost a sure shot that she will be in there, somewhere.