I've read the manual on this.
X-T2 DR.
It doesn't say anything about the raw file, as expected, this is a JPG feature. It just explains the feature and the DR level that will be applied at what ISO. It does come with the warning that "mottling" may appear in images with DR applied. I figured that they are pulling down the highlights and boosting the shadows in camera, the same way we do in LR.
John, what does "..looks underexposed at DR200 and 400" mean? "Looks underexposed" is an odd statement, isn't raw data, just data.
To the question of other raw converters, Iridient (IXT) does not display the same underexposure that LR shows. The third image in all of my examples is IXT and it is properly exposed, or very very similar to the OOC JPG.
Since I use raw exclusively, I'm back on the DR100 setting just to maintain some sanity. I using the IXT raw more and more all of the time, so this may be more academic that anything. But, I'm really curious to understand what is going on here. If this has been going on all along, I'm really surprised this is bugging me so much now and never before, I was looking at my images before, I really was. And I can go back in my library and I just don't see the difference before LR 2015.12.