About 40 years ago, Disney did a live-action television remake of "Cinderella" with a multi-ethnic cast. When we're talking about fantasy, I really don't see any reason that we have to worry about whether a white father and mother could give birth to a black child, for example -- it's magic, just like turning the pumpkin into a coach.
As far as Nikki James as Eponine, it was clear that we, the audience, were supposed to see her as a white CHARACTER, because there is no magic or fantasy in Les Miz, and her two white parents would be likely to give birth to a white child (unless Mme. T. was fooling around, which is always a possibility with her).
I know we've beaten this horse to death many times in other threads, but, to me, as long as the audience doesn't get confused, minority actors should be free to play white roles because there is still a disparity in the roles available to minority actors. Could a black man play Ben Franklin? Sure, if he's made up to look like him, and it's obvious that the character is BF. OTOH, a play about race can't reasonably use any but the most light-skinned actors to play whites, because the audience will go berserk trying to figure out who is who.
In contrast, the only time I think it is ok to use white actors to play black people is if the character is supposed to be someone "passing" as white. I once wrote a short story that took place in Maryland, during the Civil War, where the white narrator specifically comments that she'd love to have the golden curls and creamy skin of her new housekeeper, instead of her own swarthy complexion. At the end of the story, the narrator discovers that her housekeeper is an escaped slave eluding the Confederate Army, and not the widow of a Union soldier, as she pretends to be. I think that the housekeeper almost HAS to be a white actor in a similar story on stage, or the audience will guess the plot twist.
In any event, I applaud Broadway's efforts to open up what were previously "white" roles to anyone who can play them well. Casting a black actor doesn't make the character black -- "suspending disbelief" should apply to race in most circumstances, just as it applies to accepting singing in a musical as if it were talking.
Audrey, the Phantom Phanatic, who nonetheless would rather be Jean Valjean, who knew how to make lemonade out of lemons.
