I've just watched the BBC's Les Miserables series. The "demographics" of France was for sure totally ahistorical, Javert played by a black actor, Thenardier by a Pakistani-Kenyan actor, and so many black background actors that probably even today you can see that only in some major French cities. But still it didn't disturb the story, good series with good acting, faithful to the book (minus the physical description of the characters in Hugo's original ofc). I think we could only wish that people were that color blind in the first decades of the 19th century as it is portrayed in the series. So in this regard it is a denial of the racist realities of age, a kind of historical revisionism. But it didn't take away any value from the story and the acting, i can warmly recommend it.
I want authenticity, especially in historically set films / programmes and the inserting in this case which you say is black people in number in 19th Century France is done for what reason? to push an agenda, and I refuse to be spoon fed political agenda as part of my entertainment.
This also has a reverse to it by the way, the so called White Saviour and in particular Matt Damon appearing as the lead star in the film "The Wall" about the Great wall of China, the sort of revisionist history your describing actually gives license to that .......... and again I have never and will never watch that sad excuse of a film, along with Gods of Egypt and in the same token I won't watch the BBC's Troy either for having an African play what's supposed to be an obviously Greek Achillies.
I mean even the excuse of "diversity" is done with a white privilege that I can't stand (even though I hate using that term), a white TV director to satisfy his own diversity agenda to make him feel good about himself can't see that he's robbing one minority in favour of the other?
That director to meet his own subconscious diversity quota has robbed a Greek actor of the chance of playing a lead role in a history which is there's on the rare occasion a Greek actor is actually required for, and instead decided in his wisdom to just deliberately give it to a black man .......... so basically preppy white people decided that diversity is all about Black and White??
This tokenism may work with the White Liberal crowd but as someone who is of mixed race I see straight through that and the irony is not amusing.