I'm thinking the game will be pretty open, but not open to the point BotW was where you can choose to go fight Calamity Ganon anytime. Restoring the sword will probably give things a bit more structure and perhaps will be a requirement in defeating Ganoncorpse or whoever the main antagonist...
The announcement on the delay of Breath of the Wild's sequel had me feeling a rollercoaster of emotion: first indifference, followed by excitement over the brief new footage we were shown. The Zelda Theorist in me I guess will never completely fade away, so the first thing my mind turned to was...