Late 2020.

And Breath of the Wild didn't get a title until 9 months before launch. By that logic BOTW2 could be a March 2020 game. 

2020 with relative ease, for a few reasons. First it is using the same engine and probably a bunch of the same assets, which will greatly reduce development time. Secondly, based on success of the first, the development of the second probably started almost immediately.

I've been calling a BOTW sequel for months now, since way before it was announced. My gut feeling has always been November 2020, I still feel that.

A year later, is the general consensus still that BOTW 2 will be released this year?

Yikes

Late 2021

Late 2020 looking more like a longshot now. Probably early-mid 2021, so I'll say early.

I voted early 2021. I feel comfortable sticking with that prediction until we get more info that indicates otherwise.

Holiday 2021. I don't see it being ready for holiday this year. And, I don't see them just dropping it in the middle of the year. Breath of the Wild released in March 2017 only because that's when the Switch launched.

Considering Nintendo has now recently dropped the existence of two brand new big games on us that are both coming out fairly soon, I don’t know what to think anymore with botw2. It’s entirely possible Nintendo really has adopted a new strategy of not showing much of anything of their games until they’re almost ready to release. In that case, botw2 could be way way farther along than anyone thinks. Part of me thinks we could actually get a huge true reveal of the game sometime this summer with a holiday release announcement. But part of me also still thinks 2021 seems more likely. Who knows, Nintendo is more of an enigma than ever these days.