To be fair a realistic Zelda (or at least, 'fantasy realism' like OoT or BotW) instead of Wind Waker likely would've helped GameCube much more, so I'd say Miyamoto's hunch in that area was right. The Wind Waker did change visibly from reveal to release regardless though; the reveal trailer was even more cartoony and slapstick than the final product.
Personally, while Wind Waker remains my least favourite 3D Zelda game, the look of it was never the issue for me. I was fine with it from the start.