I think you’re splitting hairs a little bit but I think OoT is much more open world than open zone. Open zone is Sonic or Mario Odyssey. Oot is open world because, like Link to the Past and OG Zelda before it, it’s one big explorable map full of secrets to find at side quests to do at will.

The story progression is structured but that’s not at odds with being open world.

My prediction is that the map probably becomes one large and more cohesive map while the story remains structured.