Myth: Nintendo needs to have big surprises at E3 or they're doomed

[Asriel]

I think they need a couple of high profile announcements for 2018, but Switch's line-up for the rest of 2017 is already solid, even without further announcements. There's enough software for a first party release every month from now on:
June- Arms
July- Splatoon 2
August- Mario/Rabbids
September- Pokken Tournament DX
October- Fire Emblem Warriors
November- Super Mario Odyssey
December- Xenoblade Chronicles 2

Add to that ongoing sales of Zelda, Mario Kart 8 and 1-2 Switch, plus some major third party brands: Skyrim, NBA, FIFA, and smaller tier releases from indies and third parties (e.g. Western release of Dragon Quest Heroes), and Switch has plenty coming for a system in its launch year.

Nintendo don't need to go all out and announce projects years from fruition. That might generate hype, but it's not going to maintain sales momentum, which will come from regular first party releases, a gradually diversifying library, and building up key features, such as online. On top of that, we've seen continually that Nintendo sticks to their own schedule for announcements, including revealing Switch in October, before revealing launch details and some 2017 software in January, without damaging Switch. If anything, Nintendo's strategy so far with Switch has been solid.

Nintendo do need to demonstrate some 2018 software, but concentrating in detail on the next 6 months of software, while sketching out the 6 months after that, is actually enough for them. Switch is off to a solid start, with major Nintendo brands available and coming soon, and its first Christmas season ahead of it. Nintendo are in a pretty solid position this year, and E3 isn't going to make or break that.