I have been thinking about the recent rumors, both the Fusion rumors and the Plus&Minus rumors. Of course, Fusion is a confirmed fake, but I have noticed a few things. Iwata recent statement regarding the next platforms' brother-like status, the SoC rumors as well as Masuda's statement on the HD render made me think.
As one can see from the release dates, each main Nintendo console took about 5-6 years between themselves and their successors except their handhelds;
-Game Boy, which was released 9 years before Game Boy Color.
-Game Boy Color, which was released 3 years before Game Boy Advance.
-Game Boy Advance, which was released 3 years before Nintendo DS.
-Nintendo DS, which was released 7 years before Nintendo 3DS.
With this in mind, one can expect a late 2017/2018 or early 2018/2019 release for the next console, whereas 3DS would be continued to be developed for until about 2-3 years after the release of the next handheld. This would also make sense considering that it takes about 2-3 years to develop a console.
However, the end of the console directly coincides with the latest possible release of a new generation of Pokémon, and as stated by Iwata, the next handheld will be a brother to the system. This leads to a few possibilities;
-A repeat of Generation V, where the new console release does not change the handheld release, instead companion software are released as a means of justification for the purchase of the next game until the next generation.
-The next handheld will not try to absorb Wii U architecture literally, instead its brother will be the Wii U. This is unlikely, as not only Wii U has been a major flop and its architecture is speculated to be decreasable to be used in a handheld, but also because even if it were succesful its low end horsepower simply makes it incapable of surviving for long.
-The title's case, obviously.
-Possibly the weirdest case would be the handheld coming out before the main console, with its brother coming later. This bizzare idea might actually work, as if it is going to use Wii U architecture(or something similar to it) it can actually have a connection with Wii U before its successor, which would also use some of the same architecture to an extent for backwards compatibility. This in theory would also provide the year GF generally takes for releasing a new generation.
However, if the video concept is GameFreak's own concept, and not Pokkén Fighters' developers' concept, then it would mean that GF is already creating concepts for the next generation. And if the handheld is a modified Wii U, then there would not be a major need for the prototype hardware for the console to create the proof of concept, or even the early development. Or even the entire development might be made in Wii U development kits.
Another reason why this would be likely would of course be the time that takes for a generation. Each generation takes 3 to 4 years, and if this generation is sufficiently long(as it seems to be planned to be so), then the next generation would have to end during the end of the console's lifespan. Again, this would not be unheard of as Gen V showcases, and priorly Crystal showcases. However, this can diminish the sales further(much like what happened to Gen V sales compared to Gen IV sales), as it would essentially be for a dead console without massive improvements from visuals. The gap would not be too huge, though.
On the other hand, this would be an unconventional route for both Nintendo and GameFreak to take, and I wouldn't think it would be worth it from a capitalist perspective, as there would not be an existing install base that can catapult the sales a bit more exponentially from word of mouth and such. However, this would only matter for initial sales.
From a fanboy perspective, I also would not like this, as the update to HD can also mean that we will get another generation that is not fully realized gameplay-wise, much like the current generation is(not that staying in DS allowed for Gen V to make massive moveset changes, but it did provide it time to polish several existing mechanics and add a good region with massive selection of Pokémon to choose from that is mostly diverse). However, as GameFreak current motto is clearly simplyfing the mechanics further, this might not be unavoidable to begin with, for better or for worse. On the other hand, Gen 8 would eventually be forced for the successor of 3DS like the seventh generation, and as it would likely have the backlash of Gen 7, several gameplay improvements will likely happen then. And I can't really deny the fact that I would totally dig the updated sound quality.
Either way, upcoming three to four years will certainly be amusing to watch... probably more fun than to be an actual participant in.