Modern reimagining of The Three Musketeers make Musketeers sound more honorable and noble then actual text. Some comedies make them sound incapable, clumsy and funny. Dumas politics was not pro-ancient regime and he actually makes it clear. Making that into super honorable flawless dudes is as much "changing past fiction" as if you slapped gender or race or made them eskimos. But somehow that is fine.
> If all we see is fictional pasts where black people are just white people with tans, and women are just pretty men, what are black people and women complaining about?
In general, they complain about how they are or were treated back in real world. They also complain about being depicted in fiction as dumb simpletons without agency and then people on discussion forums claiming that those dumb simpletons depictions somehow constitute historical reality.