If you are referring to "Hamilton" using a diverse cast to play characters that were white in reality, I'm not sure that is a good example. The commenter above said "Actors should be a good match for the role they play".

I haven't seen "Hamilton", but from what I've read it has little or no mention of slavery. When you don't have slavery in a story set in that era the character's race usually isn't important for the role so the actor's race doesn't matter.

... when does the actor's race matter? It would when the story is about racial tension, I suppose: it'll be a century or more before you could have a white actor play Malcolm X. But most of the time, it doesn't matter that you've recast, say, Johnny Rico from Starship Troopers as a white character.

Regardless, the criteria above about actors needing to match their characters in every detail is risibly ahistorical and unmoored from any principle of film or theater; it's pure applesauce, rationalization pretending at erudition.