The DNG is unedited, and does not have a standard color profile (its profile might be described as “camera profile”). The image that you sent does not have colors that push the limits of the sRGB gamut. As a result, there is no difference between the narrow gamut files and the wide gamut files. Generally, you need very saturated colors to get the benefits of wide gamut (your image has neutral colors for the most part). If you look at this page, you can see images that show the advantages of wide gamut. All use very saturated colors: WebKit samples
I ran some additional experiments, using RAW Power and also Photos. In both apps, if I export your photo unmodified to sRGB and P3, the images are the same. Only if I make a larger change (saturation + white balance) to push the colors, do I get different images.
If you want to do something similar to see the difference, then apply these two adjustments: White Balance = 10000, Saturation to 2.0. You will see the difference on export.
