As I said previously, I believe that the new DVNR-ed master was made specifically because of the 3D release. I have two reasons for this belief:

A) If it wasn't for a pending 3D conversion and subsequent theatrical release, I doubt they would have even bothered making a new transfer.

B) Grain doesn't exactly look great in 3D - it is natural to a 2D film image and the human eye usually doesn't detect it as making the image unrealistic, however in a stereoscopic 3D image, the grain seems to cover 3D objects as a moving-grain layer on their surface, which is something the human eye recognizes as unnatural - For example, I have seen Avatar 3D projected both digitally and in IMAX and in IMAX the grain added by the 70mm film used made for a very distracting effect.

And I fully expect that if it ever comes to releasing the OT in 3D, appart from further meddling with the films themselves, we can expect a similar amount of DVNR applied, albeit probably to the current masters...