It is not clear that the game will switch to the sandbox yet. But if I do sandbox, I won't redo the first chapters. Only the third and subsequent chapters will be open world. (At least I think so for now.)
The thing is... if you go "open world" it'll still just be a straight story anyhow. The characters will all have straight forward paths. That's not a bad thing. "Opening" up a map and travel, etc... only makes the game more complex - for both you as the dev and also for the player. And, does the extra complexity net you any sort of advantage? What advantage, for example, do you think the game having map travel will bring to the story? Or to me as the player? All it really means, for most stories, is that I'm going to waste time and focus by needing to click around to travel to new locations, per some quest, rather than just enjoying the story.
Unless you're going to build a game as rich as Summertime Saga, for example, why bother with travel. Just create a nice story, maybe some branching decisions, and let the character move to locations on his own rather than make me get lost trying to figure out where the hell the last mission was meant to take me.
