If you did your research you would know I am not a dng advocate at all. I use nef files direct from my cameras in Lightroom generally. Simply because it is not really worth my time to convert. The dng files are smaller than nef files in general because they are much more efficiently compressed but hard disk space is not really an issue nowadays so I simply do not bother and I also like being able to open my files in Nikon's software if I need to even though I basically never do. There is one major advantage to dng which is that third party raw converters could support new cameras from day one which is what this thread was about. There is absolutely no downside for camera manufacturers to use dng instead of their own raw format except for them not having a small time window in which users are locked into their software. In fact many camera makers use dng natively to give their costumers the ability to use other raw converters than their own if they choose so. Dng stores the exact same data and were Capture NX D to read dng files, it would give the exact same rendering as the nef. The raw converter determines the quality of the image, not the file format.
History is full of examples of superior formats losing even though the technical advantages were enormous. The winners usually are determined by marketing decisions and by inertia. A good example is VHS vs betamax where Sony made the regrettable for them marketing decision to not allow certain adult material to be on "their" technically far superior system. Of course VHS became the default simply because that's where the content was that people wanted and betamax became a niche market. High def audio as Sony and others tried to promote for a while is technically far superior to mp3 or aac files but the highly compressed aac files are so much more convenient as you can put them on your iPod/iPhone and have them with you in reasonable quality instead of having to deal with discs, special players and not being able to rip them to your iPod that the high definition audio formats were complete flops. In the case of raw files, Nef is only used in Nikon cameras because of a marketing decision by Nikon to use the format lock in to try to drive their own ecosystem, not because there is some sort of secret sauce to it or some sort of extra info in it that is not in dng.
I will take that NEF, converted DNG and using THE SAME camera profile and adjustments lift up" the image from DNG and original NEF
You do that. As I showed above, if you use the same raw engine and the same development settings, your results will be completely identical not just close but bitwise identical. Doesn't matter which camera.
