the whole story of Henry V111's reign and the role of the 6 wives in it is huge and complex. its the story of a probably psychotic monarch, with absolute power, who completely changed the faith and of the nation and was embroiled in manipulating and being manipulated by courtiers Thomas Cromwell - Cardinal Wolsey, Thomas More, Cramner....
The playout of other women as well as the wives, Mary and Elizabeth....
The role of those wives in a Tudor world, and their manipulation by their families
but these are not just about events in Henry V111's reign, it ia a tale of absolute power and its consequences, the role of women broadly, the role of those close to Henry and their rise and fall of power (this is bingeing to sound like Trumo and other s who are trying to or who have "Absolute power" (as in Trump blaming that he is above the law, even the supreme court, currently
These universal themes do not demand specifically in my POV that only white Women can play the wives.
to say yet again, the purpose of drama is to engage us in the dramatic world created in that play, and therefore engaging a wide range of players including black ones engages more people, and gives us a chance to make both parallels and differences between power and its use in the Tudor world as opposed to now.