Maybe not even TPs art style. Maybe they could use a completely different darker mature art style in the game. I'm not sure how they would do that though, I'm sure they'd find a way, Just a thought though.
I'm not sure about the texture problems you speak of though in TP... Could you elaborate...
I'm kind of unsure on whether or not we'll see a dark Zelda game soon or even at all. If you look at the recent trend of Zelda games that have come out you'll notice that they've all been on the lighter side. PH and ST were both bright games but thats probably just because the "Cartoon esque"...