Nintendo had already stepped out from showing off AT E3, and instead have gone for Directs that are shown during the event. In a recent meeting with investors; Satoru Iwata, CEO of Nintendo had made sure to let them know that anything related to the NX or any form of hardware from Nintendo would not be shown.
The reason for this is that there is no news at the time concerning it. The NX was still a ‘new concept’ and that it wasn’t meant to be a replacement for the 3DS or Wii U.
Furthermore, Iwata mentions Nintendo’s ‘quality of life’ platform which again isn’t suppose to be a system replacement; and it is only meant to be a piece of hardware that’s suppose to assist in enriching the day to day life in terms of health such as sleep. Because of this, it too will not be mentioned or shown at E3.
So that’s that, with no news to be expected on the NX or the 5 mobile games that Nintendo is pushing. I can only hope that the direct will show off some new games alongside giving even more information regarding several of the games that were announced at at the April 1st Nintendo Direct stream.