A very well thought out prediction with good and solid points! I like a lot of it!
I think it all depends on whether or not it's a unified system: can you play ALL Nintendo games on both the home AND handheld consoles? If that's the case, I'm pretty sure the HH version will release WW in 2017, probably during the Holidays and the home console version will release in 2018.
If they merely use the same OS between both consoles but have individual games, I think there's a chance the HH will release in late 2016 in Japan and WW in 2017.
But I do hope they keep the dual screens actually! It's such a nice and easy way to make the screen feel bigger since there's less clutter on it.
I'm on Twitter @DanneSandin!
Furthermore, I think VGChartz should add a "Like"-button.
