lol.

Imagine crafting an online persona for the specific purpose of grinding an axe against a game company you don't like.

By June 2015, the only game we knew would be in switch was Zelda. January this year we knew the rest.
So, relax, they gave many things to show. Expect a big direct in 2018 beginning showing the 2018 games

I want to see a new 2d Mario, with new mechanic and art style that shows to be distinct from new series

Nintendo a really good year with Zelda, MK8, Splatoon 2 and Mario.
The rest, despite being good to great titles are not system sellers. At least there's nothing pointing in that direction.

In 2018 you have (for the sake of momentum)... Kirby and Yoshi.
That's not a good sign. Again, as fair as we know.

Pokémon and MP4 were announced but Nintendo has not given them a release date (easy to to see why).

There are a number of factors to consider when judging a company's first-party output.

There's the number of studios they have and the number of people they have working on games.

There's the time-frame (like how comparing outputs from 2005-2013 doesn't match up against a system which lasted from 20006-2012 before being replaced).

There's the relative quality, diversity, and uniqueness of the library.

And then there's the little issue of the split in development resources.

The only reason you are worried cause lack of 3rd party games.

Other systems have great AAA game that mask 1st party gaps.

Project Octopath Traveler, New Retro game, No More Heroes 3, Pikmin 4, Shin Megami Tensei 5, Fire Emblem 2018

other than just Kirby and Yoshi. Plus we are just halfway through 2017, and we already know about these 2018 games. There are more to be announced, don't jump to conclusions yet ;)

A couple games throughout the Wii generation? Ok. I'm pretty sure Wii wasn't dead in 2009/2010, it still got a solid amount of good games in both of those years, and sold 21.2 million units and 17.3 million units respectively. Wii really started to fall a cliff in 2011 where it sold a still respectable 11.5 million units, and got a lot less in the way of releases. C'mon, Wii U had a lifespan of at least 4 years . Same 5 franchises, do you even know what you're talking about? Off the top of my head, Super Mario, Zelda, Mario Kart, Super Smash Bros, Pikmin, Fire Emblem, Animal Crossing, Yoshi, Kirby, Xenoblade, Metroid, Mario Party, Mario sports titles, and even more. That's a bit more than 5. 

Project Octopath Traveler - no release date given
New Retro game - not announced and no release date given
No More Heroes - no release date given
Pikmin 4 - no release date given (latest comment: "it's progressing")
SMT - announced for 2018
FE - announced for 2018

So, you have 3 1st party games and 1 3rd party game announced for 2018.

Also, remember this thread was about 1st party games.

What first party franchises come out this year? 

Mario, Zelda, Xenoblade, Splatoon. 

Three of those are big yes, but Nintendo has other franchises in the wings. 

Animal Crossing for example. Splatoon's development team also does that game. If they are done with Splatoon 2 work on that can shift to overdrive. 

There are also the subteams: I have no idea what the 2D Zelda team is up to for example. Nor the Paper Mario team at Intelligence Systems. Heck even the Fire Emblem B team for Valentia could be off doing something. 

Nintendo also has the benefit of fans who really get excited for revivals of dormant franchises. Ignoring the Metroid 4 reactions from E3....

What first party franchises come out this year? 

Mario, Zelda, Xenoblade, Splatoon. 

Three of those are big yes, but Nintendo has other franchises in the wings. 

Animal Crossing for example. Splatoon's development team also does that game. If they are done with Splatoon 2 work on that can shift to overdrive. 

There are also the subteams: I have no idea what the 2D Zelda team is up to for example. Nor the Paper Mario team at Intelligence Systems. Heck even the Fire Emblem B team for Valentia could be off doing something. 

Nintendo also has the benefit of fans who really get excited for revivals of dormant franchises. Ignoring the Metroid 4 reactions from E3...there were cheers like that when Kid Icarus Uprising popped up at E3. 

Nintendo games don't have to sell as much as, say, Crash Bandicoot's remaster because 1st party games get more bang for their buck than 3rd party. Nintendo can coast a lot easier on B selling franchises and even C selling ones than Activsion can. 

With just how many Nintendo franchises are now major sellers and hype makers, plus new games, remasters and remakes (even if not Mario ones), Nintendo should be fine as long as the quality of the 1st party is good and sustainable. 

Ultimately, it is as you said, there is more to be announced. Nintendo hasn't put everything out there yet and we'll probably know more of what's to come later on in the year and beyond when they're ready to announce more. Nevertheless, I have to say that seeing what's going on this first year for the Switch in terms of first party, I don't know what launch year first party lineups of consoles' past matches up to that. Sure some have great launch lineups, but for the whole year?