That's fine, but Amazon isn't rewriting his books. I think it is impossible to infer Tolkien's reaction, and furthermore, quite silly to try and enforce that inferred reaction.
Take the Wheel of Time series. A lot of unhappy fans again. Robert Jordan isn't around to give his opinion, but Brandon Sanderson finished off writing the series after Jordan's death and has talked about what he thinks of the TV series. His comments are remarkably less hysterical than what fans say. He basically says he likes it and there are some things he would have done differently [1].
Ghost in the Shell is another example. The live action movie was bad. There was a whitewashing controversy about a caucasian actor playing the lead role. The original Ghost in the Shell anime director came out and said it didn't matter [2]. His comments are worth reading:
> ...Oshii said that because the main protagonist – Major Motoko Kusanagi – is a cyborg, the question of race and whitewashing is a moot point. “What issue could there possibly be with casting her?” Oshii said. “The major is a cyborg and her physical form is an entirely assumed one. The name ‘Motoko Kusanagi’ and her current body are not her original name and body, so there is no basis for saying that an Asian actress must portray her. Even if her original body (presuming such a thing existed) were a Japanese one, that would still apply.”
Oshii added that he thought Johansson was the best possible person to play Kusanagi in the Rupert Sanders-helmed remake, which is out next weekend in the US. He also argued that actors of different backgrounds from the characters they are portraying is part and parcel of the film-making world.
”In the movies, John Wayne can play Genghis Khan, and Omar Sharif, an Arab, can play Doctor Zhivago, a Slav. It’s all just cinematic conventions,” he explained.
”If that’s not allowed, then Darth Vader probably shouldn’t speak English, either.”
That raises a kind of interesting point. They aren't rewriting his books, they are rewriting his world.
Tolkien started out with a hobby of creating languages. He then was inspired to build worlds in which those languages would live. His fiction came out of a desire to have adventures in those worlds.
I've read descriptions of Tolkien's dealings with people who wanted to adapt his published stories for film. He was quite ready to accept modifications to the stories to fit the needs of another medium, so long as the main thrust of the narrative was preserved. What would really draw his ire, though, was when people tampered with his world.
All that said, though, his writings, especially later in life, give me the impression that if it were explained to him that racial diversity was to become the hang-up for people that it has, he would have sought to modify his stories to avoid giving offense.
Take the Wheel of Time series. A lot of unhappy fans again. Robert Jordan isn't around to give his opinion, but Brandon Sanderson finished off writing the series after Jordan's death and has talked about what he thinks of the TV series. His comments are remarkably less hysterical than what fans say. He basically says he likes it and there are some things he would have done differently [1].
Ghost in the Shell is another example. The live action movie was bad. There was a whitewashing controversy about a caucasian actor playing the lead role. The original Ghost in the Shell anime director came out and said it didn't matter [2]. His comments are worth reading:
> ...Oshii said that because the main protagonist – Major Motoko Kusanagi – is a cyborg, the question of race and whitewashing is a moot point. “What issue could there possibly be with casting her?” Oshii said. “The major is a cyborg and her physical form is an entirely assumed one. The name ‘Motoko Kusanagi’ and her current body are not her original name and body, so there is no basis for saying that an Asian actress must portray her. Even if her original body (presuming such a thing existed) were a Japanese one, that would still apply.”
Oshii added that he thought Johansson was the best possible person to play Kusanagi in the Rupert Sanders-helmed remake, which is out next weekend in the US. He also argued that actors of different backgrounds from the characters they are portraying is part and parcel of the film-making world.
”In the movies, John Wayne can play Genghis Khan, and Omar Sharif, an Arab, can play Doctor Zhivago, a Slav. It’s all just cinematic conventions,” he explained.
”If that’s not allowed, then Darth Vader probably shouldn’t speak English, either.”
[1] https://winteriscoming.net/2022/01/27/how-brandon-sanderson-...
[2] https://www.theguardian.com/film/2017/mar/24/scarlett-johans...