ACR/LR > DNG converter > DNG SDK
This is not what Eric says, see the following quote (note that the bold text is my highlighting and not in the original message):
Yes, DNG is a documented image file format (basically an extension of TIFF) that can be used by anybody, but there have been revisions to it since its introduction. Just like there are multiple versions of JPEG, TIFF, MPEG, etc.
Yes, the DNG Converter will allow you to process a new raw image in an older version of ACR.
It is true that the public DNG SDK only contains a simple bilinear demosaic implementation, but the DNG Converter does not use this.
For operations that require a demosaic step (e.g., conversion to 3-channel RGB), DNG Converter uses the same demosaic algorithm as Camera Raw, assuming the same version. For example, DNG Converter 6.2 and Camera Raw 6.2 use the same demosaic algorithm. Similarly, DNG Converter 4.4 and Camera Raw 4.4 use the same (older) demosaic algorithm. Newer versions of DNG Converter offer more camera support, have bug fixes, and improved features over earlier versions. For this reason, I generally recommend using the latest available version of DNG Converter (currently 6.2, soon to be 6.3), regardless of which version of Camera Raw you are using.