Based upon how I see the games going, I guess I should provide some feedback to this thread as well. I've noticed that more technology has appeared in the cel-shaded Zelda titles instead of the...uuhh...other looking ones. Ocarina of Time, Majora's Mask, and Twilight Princess had their own technological innovations (i.e. bombchus, clocks, and a gear-based top), but I don't think any of those games have made reference to the steam engine, which appears quite often in Wind Waker, Phantom Hourglass, and Spirit Tracks.
To be honest, steampunk works out great in the cel-shaded titles simply because they can pull it off greatly with the cel-shaded visuals without being awkward. However, the art style of games like Twilight Princess make me feel as though it must be restricted to medieval without feeling like it's stepping out of the realm of what was possible back then. I'm starting to enjoy steampunk, but it truly depends on the title and how they pull it off. I can defiantly see the Hero of Winds and his descendants living in a steampunk world; but for the Hero of Twilight, not so much.
So, to answer the question of the thread, it truly depends on if it's an adult timeline game, or a child timeline game...yeah, that was weird saying, for I'm not really a timeline theorist.