That's flawed thinking, because there is no such thing as 'right' or 'wrong' when dealing with any adaptation. There is zero way any adaptation to be 100% faithful to text, especially when there are ambiguities such as the complete lack of description of what Elves or Dwarves would actually look like.
Like the pointed tips of Elf ears? Not in the original text. Elves are described to look so similar to Men that they could be confused for them, and their eyes and voices are their only distinguishing features. By this measure, no modern visual adaptation of Middle Earth's Elves is 'right'. But that doesn't make it right or wrong, because adaptations are free to depict Elves with pointed ears, to the point where it's become widely accepted.
If you're a stickler to your own definitions, then all modern visual adaptations of Tolkien's Elves is wrong. Does it even matter? I don't think anyone would think of an Elf any other way. The creative liberty has become a part of how people recognize Tolkien's Elves. I'd say the same with modern depictions of Balrogs with actual wings.
The original canon isn't so much a blueprint as it is a guideline. Text does not translate to the big screen, that is why we're talking about adaptations.