It looks like Nintendo isn't planning to launch the Zelda Breath of the Wild sequel till sometime after March 2021. Nintendo just published on May 7 its financial results for the last financial year, which ended on March 2020. The results are detailed through two documents in Japanese here and here.

Nintendo, in the documents, detailed the announced content that will launch in the current fiscal year, ending on March 31, 2021. The list includes Xenoblade Definitive Edition, Sekai no Asobi Taizen 51, Famicom Tantei Club, and DLC content of Animal Crossing, Pokemon Sword and Shield, and Super Smash Bros Ultimate. However, there is no mention of the sequel of The Legend of Zelda Breath of the Wild.

The Breath of the Wild sequel was announced at E3 2019, meaning it falls into the "announced titles" category. As such, this means Breath of the Wild's sequel shouldn't be launching before March 2021. Shoutout to our Japanese peers at Game Watch for pointing it out.

Zelda Breath of the Wild sequel reveal trailer:

Nintendo revealed the Breath of the Wild sequel with a trailer at E3 2019. It most notably features a scene showing something happening to Link's arm. Whatever that is, I can't help but be reminded of Space Adventure Cobra. Many players around the world are highly anticipating this sequel, seeing how much of a masterpiece the original game is. One popular theory is how this sequel will be much darker than the original Breath of the Wild. Personally speaking, I'm not very fond of dark atmospheres, so I'm hoping this won't be the case. As long as the game has deeper story content, and a more profound battle system, that alone would make me happy, and could be enough for the sequel to surpass the original. In any case, we might learn more in June, during the traditional E3 period. It'll be one year since the game was announced.