Really? You are really having to ask that again?
It doesn't support DNG files as such, it only supports specific camera models. See Jim's posts above re this.
LR supports DNG files from any camera, no update needed which was a, if not the main reason for establishing the idea of DNGs.
The reality is people buy new cameras and then ignorantly whinge at Adobe, Apple Etc that their new camera is not supported by software which was designed long before the camera was manufactured. Apparently the only difference in a raw file that breaks the compatibility can be as basic as the model name. Which is something I recall someone like Thomas Knoll at Adobe saying at one point.
If Leica, Pentax etc release a new camera you can work on your raw files as soon as you get camera. No waiting months for a software update, after some pointless reverse engineering has been done.