Here are the solutions:
A) It's fake, photoshopped.
B) Nintendo left it up there for a little while to get a buzz going. I mean, it's obviously referencing Majora's Mask. (A bit scary that Dawn of a Final Day coincides with the 21st...)
C) They didn't mean to announce it yet and realized they fucked up and we should watch for a Nintendo Direct or something coming up.
D) Nintendo was just dicking around.
A) It's fake, photoshopped.
B) Nintendo left it up there for a little while to get a buzz going. I mean, it's obviously referencing Majora's Mask. (A bit scary that Dawn of a Final Day coincides with the 21st...)
C) They didn't mean to announce it yet and realized they fucked up and we should watch for a Nintendo Direct or something coming up.
D) Nintendo was just dicking around.