rijnland

I am afraid it will not work. The nauticam nikonos adapter already places the Nikonos lens at the correct distance from the NEX sensor so it's image will be in focus only without additional adapters. The metabones adapter will do the same when used directly between the camera an the lens it converts (if they ever make one that fits your nikonos lens..) But then the combo will not be watertight, and there is not much use in putting an additional port around the 15mm+adapter combi.
It will work with e.g. full frame canon lenses, for macro this might be a good solution, if you can find a port that fits.

I just got the Sea&Sea 12mm f3.5 fisheye for nikonos fit to try on the NEX with the nikonos adapter. Will give almost the same field of view compared to the 15mm on full frame, only this is a fisheye...

However advanced the technology will get, the better the picture is when you take it, the more flexibility you will have in post-processing. With high resolution lenses and even higher resolution sensors even serious cropping will still yield an very good image. But the laws of physics are pretty strong, and there is a definite maximum to the resolution possible due to many things, an important one the wavelength of light. I feel you should always try to take the best possible image when you shoot it. Cropping the eye of a plastic duck from a 1:1 macro image to a higher magnification is possible because it was shot with a high-res macro lens to begin with. If this eye was a tiny spot on the soft corner of a WA lens, you will never be able to obtain the same resolution, however skilled you are in photo-shopping. Modern technologies give you more, but certainly no unlimited flexibility.