As I explained, it doesn’t, which is exactly what my point is. If changing a race of a fictional character doesn’t add to the story, then why would you change it?
It was already changed once to make it white by Disney. Anderson, the original author, certainly didn't do that. If you're opposed to changing it your beef is with Disney for making Arial white when it wasn't stated she was from even from the beginning.
As in there is more value to keeping true to the original character, regardless of their race.
No there isn't. Many of the historical characters in fiction in our western culture can be traced back to our racist past. Keeping that pattern merely reinforces that exclusion. This is especially true where it adds no value to keep it exclusively white. An even more extreme version of this is historical white actors playing minority characters playing up obvious racial stereotypes. A great example of this is Mickey Rooney playing the Japanese character of Yunioshi in the 1961 movie Breakfast at Tiffany's. If there was a reboot made of this movie today, would you argue that another white actor should play the Yunioshi simply because Rooney, a white man, played the character in the original telling? The author of the novella, Truman Capote, certainly didn't say the Yunioshi character was a white man pretending to be a racial trope of a Japanese man.
Changing it sends the message that there is something better/worse about certain races (in general or in the specific story). I don’t support that (unless it adds to the story).
Thats a really strange take to me. I could use nearly the exact words in my argument to support having other race actors play the parts. You're arguing the fake creature a mermaid's human half should stay white because it would be worse to have a black actor playing that part.
Maybe that’s not the message you get when you see race swaps, but I usually question motives behind decisions.
Not even a little bit. Did it upset you when the Broadway actor Leslie Odom Jr. played the part of Aaron Burr in the Broadway musical Hamilton? The historical figure of Burr was a real person and objectively white, but Odom Jr, a black man, played him on stage. Did you find that inappropriate or importantly un-authentic?