Back in April, Nintendo announced that The Legend of Zelda: Breath of the Wild was delayed to release simultaneously for both the Wii U and NX in 2017. At that time it was also revealed that the NX would see a March 2017 release date.
During the last Nintendo Direct, a number of Zelda themed amiibo were revealed for a December 2 release. These amiibo would have special functions in Breath of the Wild, in addition to those, the Nintendo store has listings for even more Zelda amiibo – except those are scheduled for vague '2017' release.
Two separate individuals have come across two Zelda amiibo that had been set for a 2017 with a firm release date. It appears to be a mistake on Nintendo's part, but at the bottom of the amiibo store on the Official Nintendo website, a few of the coming amiibo figures are getting release dates when they shouldn't have one.
The first person, from Reddit, came across the listing on Nintendo and took a screenshot (above). Then a NeoGaf user attempting to replicate the event came across another Zelda amiibo with a release date (below).
The release date? March, 4th, 2017 (it's a UK based site).
Unless the amiibo are getting released after the NX launches… It looks like that will be the date for the NX's release! You can try to replicate the leak for yourself here, scroll to the bottom of the site and look at the random four amiibo that appear at the bottom of the page under 'Discover more amiibo.'