I think you guys are underestimating the power of Animal Crossing on a handheld. Animal Crossing: New Leaf has sold 11.23 million on the 3DS so far. Even Animal Crossing: Happy Home Designer managed to cross 3 million units. In Japan, a new mainline Animal Crossing game on a handheld is a monumental release that rivals even Pokemon now.
I know Animal Crossing has a reputation as being a casual game, and it certainly leans in that direction very strongly, but you can't sell those kinds of numbers without capturing a good amount of the more dedicated gaming audience too. I seem to recall that New Leaf had a lot of fans on the NWR staff, for example. Nintendo would obviously still need more titles aimed at dedicated players, but I think Animal Crossing is absolutely a game that could be their major 2018 release. The fact that Animal Crossing: Pocket Camp is coming to warm people up helps too.
I don't think Pokemon Switch is a 2018 game. These were Ishihara's comments about Switch in an interview that went up in early September:
“I told Nintendo that Switch wouldn’t be a success before it went on sale, because I thought that in the age of the smartphone, no one would carry out a game console. It’s obvious I was wrong. I came to realize the key to a successful game is quite simple: software with absolute quality leads sales of hardware.
The fact that the president of The Pokemon Company seemingly had such little faith in the console until, apparently, some time close to or after launch does not really make it seem like Pokemon Switch has been in development for a long time. When you consider other factors like this being the first HD mainline Pokemon game and that Pokemon and Switch's demographics should line up much better in a couple of years (when we might see a revision and/or price drop as well), I think a 2019 release is much more likely.
Shin Megami Tensei V is another one that sounds like it's pretty far off. Koizumi said that Atlus had just started development on the game at the January event when it was announced. We didn't get a release window last week when it was officially revealed as Shin Megami Tensei V, and the director of the game would not commit to coming "soon" in a Famitsu interview that was published shortly afterwards.
Regardless, I'm really looking forward to seeing what we do get on the Switch in 2018. Nintendo's output in 2017 so far has been absolutely incredible (and we've still got Xenoblade Chronicles 2 coming in less than five weeks), and Fire Emblem Switch, on its own, is enough to get me incredibly excited about next year.