I don't blame you! We're almost two months into the switch coming out now, so yeah, that's completely unacceptable. How long ago did you order it?
I kinda panicked a bit when some of my stuff kept having the pre-order dates get set back eachj time. But if its any consolation though, even when that happened to me on the PDP case, as it's on a reservation system Amazon still dispatched it when they said they would despite the dates on the page going up. SO I think any new dates only count for new customers placing fresh orders (except for truly pre-order stuff that hasn't yet been released, which they really can shift the real dates on you for). But I think those zelda skins have actually been out though, and that they just can't make enough to supply everyone. So if that's the case, yours will probably be reserved, and you might be okay. Still annoying though when it happens,especially when you're looking forward to stuff.
Got a nice surprise with some date changes the other day though, where it happened the opposite way round. The Darksiders Warmastered Edition game for WiiU that I had pre-ordered that was previously saying December 2017 (and to be delivered in January 2018), now seems to be saying that it will come on May 23rd this year. (So I don't mind when it happens that way round) www.amazon.co.uk/gp/product/B01JIQYYGC
Wish I could say that the switch stuff would all be that easy (and super Mario Odysee seems to show some quite conflicting dates between the usa and uk amazons, so I reckon that both of those are just guestimates, and god knows which will be the true date in the end for that one).
Thankfully the mariokart wheels all seem to be in stock though, so looks like both of the ones of those I ordered should arrive on time at least. (though I had better not tempt fate on that one) lol.