I honestly don't know what to tell people who think it's going to be delayed.
There's really not much pointing to the delay other than "It hasn't been revealed yet so it's OBVIOUSLY being delayed." which is stupid. I feel like most of the delay train is coming from people who are just salty that there hasn't been a reveal and people who are always negative about Nintendo(not saying you can't be, but a lot of people are overly negative) which seems to be a large part of NeoGAF.
Do you honestly think that Nintendo can afford to delay this thing? They can't. It's simple as that. The 3DS is on its last legs and the 3DS direct was almost 100% a blowout of the rest of Nintendo's 3DS lineup. The Wii U? It's already dead. It has Color Splash and Breath of The Wild, after that? Nothing. I mean, look, lying to fans is one thing, it's bad, but lying to investors? That's even worse. The NX needs to come soon, by March. Investors are already getting a taste of that oh-so-sweet mobile market. Investors have already been pushing mobile for A LONG time, and you can bet your ass that they're gonna push even harder for more mobile when they see how well Mario does. They're going to push hard if there isn't something else to keep them in check. Of course Nintendo wont crumble under pressure and go all mobile, or even make more mobile plans because of it. But they might lose investors.
As far as we know, Nintendo has officially stated March 2017. There are very few(if any) credible rumors to back up a delay. In fact, if you just use logic you'll see it doesn't make any sense.