A sea limited by the technical requirements of a 2002 game may be boring (to some), but I disagree in the bigger picture today. ToTK already shows us what multi-tiered map design can look like. The sky and ground are superbly different in their focus and complimentary, just as a continent next to a sea could be as well. Add in underwater segments (swimming sure, but underwater cities in air bubbles, temples, so on too) and all the new mechanics that could follow... See my other post in this thread for what I am imagining. Just like how BoTW was inspired by the original Zelda... I'm talking inspiration not sequel. Which, TBH Wind Waker's influence can already be heavily felt in BoTW/ToTK anyway with regard to an intention of open-ended adventure.
The point of my post that you quoted is that a new Zelda title inspired by WW in 202X looks nothing like WW of 2002, and frankly is likely nothing that any of us can easily imagine. The Zelda team will always surprise us and go places we don't expect, as is evident with ToTK.