If Helen of Troy can be portrayed as Black simply because sheโs a fictional character, then Black Panther can be played by a Mexican actor for the exact same reason. Both are made-up characters, so the โitโs fictionโ defense should apply equally to everyone. Any character should be able to be any race if weโre truly going by that logic.
If a characterโs race truly doesnโt matter, then no one should get upset when the race gets changed in either direction.But if people lose their minds when a beloved Black character is made Mexican, then clearly race does matter to them. In that case, no character should deviate from its original cultural and ethnic intention.
You canโt have it both ways. Either race-swapping is always fine because itโs all fiction, or the original identity should be respected across the board.