I think you guys are going too old look wise for t'challa..
Hopefully he gets his own movie and they can have him as the young prince returning to wakanda from being educated outside of Africa.. Then you have the elders and locals giving t'challa crap..
Then his father is killed early in the film.. And he has to become king and thrusted in the black panther role
Morris chestnutt is around the same age as those actors mentioned and i dont think dude would mention black panther unless he new something so maybe they are going in a different direction. If not then maybe the role of his fsther?