Higher resolution for video games is not a new concept. That has been done several times before.
The first quote you provided says neither Wii U or 3DS which is the same thing Iwata said. A new way to play games (a brand new concept) obviously refers to control input while "pure replacement" doesn't divert from what Iwata said before either. Kimishima is merely repeating what Iwata said. The words are slightly different because the translation isn't an official one from Nintendo.
The second quote means that the Wii brandname will be dropped. Nintendo systems have had various names, so a new Nintendo system having a different name and succeeding an old system isn't anything new either. Considering how the Wii U sold, it's no surprise that Nintendo would drop the Wii brand.
As for my sources, the already provided quotes do the job already. Your interpretation of the quotes is flawed, that's all. You are on a sales website, you know how terrible the Wii U is selling, so why would you expect that NX won't succeed the Wii U? Why would Nintendo spend additional resources on Wii U games when the system is as good as dead? NX was always going to succeed both the Wii U and 3DS since Nintendo had already talked about combining their R&D departments for home consoles and handhelds, because the technological differences weren't as pronounced as they were before, so keeping home consoles and handhelds as separate entities wouldn't make sense anymore. The benefits would also apply to game development, hence why NX was not to replace 3DS or Wii U, but rather 3DS and Wii U.
Nintendo had to find a way to support both a home console and a handheld with first party games on a more consistent basis, and when you know that, you can make the next logical step and rule out that Nintendo will support 3DS, Wii U and NX all side by side. When NX launches, the end of 3DS and Wii U will be near. Nintendo won't support three separate platforms, but only one that consists of a home console device and a handheld device. That platform is NX.
You can read up on Nintendo's Q&A sessions with investors on this website. Scroll through the newsfeed and look for "Q&A" to access the various sessions. The earliest hints at NX date back to early 2014, so a good year before it was announced. Early hints include the mention of combining R&D departments for home console and handheld, measures to improve the quantity of first party software output and the intention to redefine what a video game platform is in a good two years (that would be 2016, but alas, eventually NX got delayed). It may seem lazy that I don't point you directly to all NX-related information, but there have been a lot of Q&As over the years. Check it out if you are interested.