I think we can suss out what's happened here with some supposition and some tie-ins to the rumors we've heard floating around from more reputable people with some connections. I think the NX 2017 result is from a domino effect of events that simply put the launch in 2017 as a better proposition for consistency than the 2016 Holiday launch. This seems to be a move done entirely for momentum conservation in the long run rather than the short term affects of the holidays.
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If you recall, not long ago Zhuge had been hearing of a potential staggered release schedule for the different regions for the NX. That is to say certain markets were to see it before others, and one would think this is because of production concerns and simple feasibility of time-tables for full production runs to be able to feed the markets. We also had the internal NoA leak which most definitely had Zelda and NX pegged for this year in the states. So there was very much an expectation internally (at least early on in the year) for the NX to hit the 2016
holiday for North America at least. Potentially, Japan would have seen it later on and Europe may well have launched in unison with the States or later with Japan. In that time frame we also had heard little to nothing on the handheld variant which many expected to hit Japan.
At a glance, it isn't unreasonable to conclude that production in hardware may well have played a major role in this delay but this is only part of the story. (You can believe 14nm delays as a reason if you wish.)
The next set of rumors revolved around software and, potentially, trouble in development with certain ports (SMM, Splatoon). Zelda has also now been delayed into 2017 citing Q&A and improvements in such. Factor in
this tweet, and I suspect something on the software end got shaken up. They most definitely made a concious decision to remove all NX software from this E3 when the NX launch for 2016 fell through.
With SDKs at least out in the wild, it is also possible that software from outside parties also was simply not shaping up in time just yet but I am focusing purely on internal machinations.
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The reason I believe they aren't bringing anything NX or NX software to E3 is a simple one: they want it to be shown in one set and not in split sessions. Any software specifically for the NX won't be shown without the NX, Zelda is the only title that is left that can be shown in any fashion without compromising whatever it is that Nintendo wishes to keep close to the chest with the NX or muddying the message with long pauses in information (with regards to the new system). This E3 is going to be one focused on Zelda and the last of the Hurrahs for the WiiU, and then the various swathes of 3DS software and localizations still coming in which will/should hold the holidays on the handheld end at least.
Now if we put all these rumors together, I think the story is a simple one that Kimishima somewhat touches upon with his "waiting on games" but its only half of the tale. I think that, when Zelda hit Q&A issues and hardware development was not reaching full capacity for a 2016 worldwide launch, that corporate looked at the situation and found it better to delay everything into early 2017 then launch partially in 2016 both in terms of software availability and worldwide presence. The "waiting on games" message is also one that I do not see focusing on launch but being a more long-run statement about making sure that the launch year is actually scheduled with most software well into Q&A or finalizing development rather than all in development or otherwise.
As noted at the start, I think a bunch of extenuating circumstances have resulted in this transition, and that Kimishima+corporate have decided it best to sacrifice the holiday for a clear message in late 2016 for launch in 2017 with a defined software schedule, worldwide presence, and software to carry launch momentum past two months (ala WiiU).
