At the risk of being shouted down (figuratively, of course), I think maybe Dave and I are saying the same thing about ethnically diverse casting: The race of the actor does not matter. Sometimes the race of the CHARACTER matters, and sometimes, it does not. I still think that Christine, Raoul, and the Phantom should be white CHARACTERS, regardless of the race of the actors playing them. I also think that Eliza, Higgins, Mrs. Higgins, Freddy Eynsford-Hill, Alfred Doolittle, and some of the others in MFL should be white CHARACTERS. Pickering can be anything as a character. In fact, if Pickering were a nonwhite character, that would show Higgins' general lack of bigotry.
A recent movie starring Meryl Streep, Kevin Kline, and Audra McDonald showed how race-neutral casting for a major character should work in realistic movies, but I don't think plays and musicals have to be as rigid in keeping casting consistent. Audra McDonald played Kevin Kline's second wife, who raised the kids he had with the Meryl Streep character. By casting an actor of color, the producer and director opened the movie to a great many black background actors, because the stepmom's black extended family attended the son's wedding, which was shown in the film. The reason that consistency is important in realistic movies but not in the theater is that we all expect to have to suspend disbelief to a greater extent in the theater than in film.
Back to Dave: Where Dave and I part company is when make-up is permissible and when it is not. I don't think anyone would care about dark make-up if it were not for the history of disrespect shown by the white theater, film, and TV establishment through the use of "blackface," "yellowface," and "redface." However, because of that shameful history, changing a white actor's race through make-up rightfully makes people squirm. On the other hand, using whiteface on a person of color to play a white character does not bother me in the least because it can help avoid confusion when an actor of color plays a white character.
Audrey, the Phantom Phanatic, who nonetheless would rather be Jean Valjean, who knew how to make lemonade out of lemons.