Their E3 is now a big direct. Nintendo is ahead of the curve on this one since E3 is is losing significance.
ahead of the curve?
Nintendo was struggling to bring as much firepower as Microsoft and Sony because none of the third parties had games on their systems aka, no trailers to be shown at their show.
Nintendo's own exclusive is not as showcatching as the other 2. For example, Sony can easily show 3-4 AAA titles any given year while Nintendo can only show either Zelda or Mario and then they are dry.
Feeling the above 2, knowing Nintendo, they probably choose to save a few bucks on the conference cost and do a direct instead. So they are still in the game and have some exposure but don't have to try so hard every year in a battle they never win.
It is just like how Microsoft doesnt announce console sales numbers and says they "focus" on user engagement instead.