There's a piece missing from the equasion: Whenever a character becomes someone of color not from the source material to drive the purists and right-wingers batty, THIS IS ALWAYS A FICTIONAL CHARACTER. Not a real-life person. Applying the 'woke' rant to the biography of a real person doesn't work (Hamilton aside).
The next Ghostbusters will have women, the next Cinderella will be black, the next Captain America will also be black, but at no point will Thomas Edison be played by a Japanese actor and Greta Thunburg's life story's actress will be a blue-eyed light-skinned young woman with a Swedish accent -- and will not be played by a Jamaican.

But to play devil's advocate for a few seconds: What's funny to me is when an actor is cast for a part which is within the correct demographic, but sensitive people will still flip out because the actor is not the EXACT criteria. By that I mean: Thandiwe Newton is light-skinned black woman and appeared in God's Country, and the character she was playing was darker, so people felt that darker-skinned actors were overlooked for her part. I recall some story about a black actor playing Bob Marley having to darken his skin to correctly match Marley's fleshtone, then being accused of "playing blackface" as though he was a white guy in vaudeville. Lin-Manuel Miranda cast plenty of Hispanic actors for In The Heights, and received grief that there weren't enough leading actors who were Afro-Latinx like the people in the neighborhood the play takes place in.