Nope...sorry, Only current versions of ACR are updated. You'll need to download the DNG Converter 8.6 RC and convert to DNG.
So, the ACR for PS 5.1 was good enough for the Nikon D800, but not for the D810. I guess I just don't understand what a "current version" is, then.
Current Version means whatever Adobe is selling and therefore supporting at the time the camera is released. Right now, that would be PS-C6, PS-CC, PS-CC 2014, and Lightroom 5, and maybe Elements 12, although sometimes the last update of the summer doesn’t get to Elements at all.