Happy New Year! Here's hoping we get BOTW2 this year! I know it's a long shot, but it's not impossible, it has been almost 3 years already and it isn't like they can't reuse some assets.
I think there is a good chance of BotW 2 as a holiday title this year. They're using the same world, though hopefully at least superficially heavily altered, which means they can re-use a lot of the assets and well obviously not needing to build a giant open world from scratch should cut off a huge amount of dev time. I'd be sorta surprised if BotW 2 wasn't the big holiday title this year. The last DLC pack for BotW came out Dec 2017 right? That means they'll have had almost 3 years to take the game from start to shipping, which I would think would be enough time given they are re-using the BotW world. I'm very interested in what they change to make it feel like a whole new game.