othermen:
Yes. Increasingly, the British throne is not averse to diversifying its descent. While, as at now, the possibility is that of a mixed race, and not a person with full African ancestry. In generations to come, a black person can emerge.

If the firstborn of Prince William, Prince of Wales marries a black person. Prince George is second in line to the throne, his firstborn surely will be king. But the firstborn will be a mixed race. Obama is a mixed race; if he is black enough for you, then substitute ‘mixed race’ with ‘black person’.

To those referring to ‘ostracism’ - Harry would not be king and this is no predicated on any decision he has made. He is not the first born Prince, there was already Prince William and his children. Except, by some unfortunate means, such as the event where they all perish (if we live in the seven kingdom of Westeros ‘Game of thrones’, this is a distinct possibility) or become ineligible ( either by renouncing their claim or converting to a faith that is incompatible with being the British monarch. Then Harry would be and then Prince Archie, who have got Meghan in him, would be king.

Parliament also has power to change the law of succession, this could make Prince Archie emerge. ( This is possible, but highly unlikely, because it will be extraordinarily strange)

Yes, I mean mixed race and not pure blacks