I could see Nintendo re-using a lot of assets from this to make a new game ala Majora's Mask extremely fast in maybe...3-4 years. I sort of expect a 2D Zelda next year, though.
I hope the new Story Quest is meaty, though.
The Hyrule Wars idea at GDC seemed odd and out of place, but what Breath of the Wild set up... I wouldn't mind a prequel where you control a Goron/Rito/Zora/Gerudo Champion during the "good times"
Hyrule Civil War.