For the moment, ignore DNG as it doesn't really play a role here...
Demosiacing is only one part of the raw processing pipeline, in addition to demosiacing the raw data (usually a Bayer array), the raw processor must also make adjustments from camera color into a color working space. None of this is actually done to the raw file until it's actually processed into a rendered file such as tiff or jpeg. Until that time, the adjustments are stored in the .xmp sidecar file–hence the "parametric" edits...
As it relates to DNG, generally, unless you change to DNG settings to produce a linear DNG (a demosiaced, linear file) the DNG file contains the same raw data as in the original raw file. In this case, the DNG is simply a file format wrapper for the original raw data.