I don't think a few days were enough to change their plans.
If they actually intended on bringing those games in 2018 they would have said it so. But no, we heard, instead, "started development" or "now in development".

I don't even think a year would be enough for Pokemon. At least, not this time, seeing as how they are still busy with the 3DS games.

But that was what E3 should have been for: use the hype and media to your advantage.
Sure, they will reveal more of their 2018 plans. But unless they come out with a repeat of a january's presentation, an announcement here and there won't have the same weight.

I feel that it's very possibly true of Metroid 4 which would indeed be quite impressive, but managing to get that Pokemon title out there would be rather amazing. Seems more like a year 3 release than a year 2 release.

This is an unfair question since we do not know much about the 2018 lineup.

However, we do know these games can take years to make and I would not doubt the idea that neither is actually ready next year. Maybe one is and one isn't and even worse, both could be but because they do not want to have the games compete against each other, one gets released next year and one the year after. You never know how these things will work out.

To be fair, the Pokemon Company guy did say that the game was likely to come out in a bit over a year, which would put it in Holiday 2018.  And keep in mind, we don't know how many people are working on US and UM, those may have pretty small teams.  And on top of that, they could have begun HD asset development before Sun and Moon even launched.  We don't know enough about the inner workings of Gamefreak.  I mean shoot, we didn't even know they had a team working on that Tembo game until it was announced. 

Like I said, Metroid is the most doubtful, just due to the nature of the game. 

I believe they don't want to make the same mistake they did in 2013 and what Sony has done to themselves now:  announce a lot of far off games and then wind up repeating yourself.  So we'll see. Directs are becoming more and more common knowledge and I think Nintendo likes the lack of competition that having their own announcement events brings. 

Nobody has addressed this, but during the E3 2017 spotlight (this is speculative) Pokemon CEO Tsunekazu Ishihara looked emotionally depressed when he announced that a Pokemon Switch game was in development. I interpret this as an attempt to rectify the extremely negative feedback of the Pokemon Direct just before E3. It's as if, instantly he decided to start working on a new Pokemon game for the Switch based on the vociferous outcry as it left both him and the fans in disappointment. So, I very much doubt that this Pokemon game has been in development before the Switch was released.

Either
a) Game Freak are going to push for a 2018 release and work hard on this new game (maybe reuse some HD assets from mobile?)

b) No 2018 release at all. Misconception.

Seriously, I hope Pokemon does not come out next year. They need a break.

I'm hoping we both eat crow.  I was expecting 2020 for Prime 4 and I figured it would be like Zelda BotW where we got this little tease and didn't hear much over the course of the next couple years and we would see even less.

If Metroid isn't even in showable form right now how can it be ready for next year? I don't buy it.

I don't believe this for a second, but if it turns out to be true I'll be happy...

I always said Pokémon is a November 2018 game. Metroid will probably get delayed, but still... if one of those 2 come next year it will already be amazing.