If I understand correctly what's happening here, a single scan is split into three versions, each with a "-1, 0 and +1" (stop?) exposure, then merged together in the same way a multi-shot HDR would be?
If this is correct, while it may have some effect on the image, it's basically just a post production grading technique that could also be done with curves or multiple-layer or multiple node color correction. It's not really extending the dynamic range, or getting any of the benefits of scanning the film at two or three exposures and merging them. There is a significant difference.
With a true HDR scan, you get three things:
1) Extended dynamic range by scanning for the dense, normal and thin areas of the film, then merging them into a single SDR image. The end result is detail in all three ranges. A scan done for the shadows would blow out the highlights, and vice versa.
2) Depending on how it's done, for color images you get more bit depth in the resulting file than you would with a single scan
3) Reduced noise (if there's noise in the scan in dense areas of the film, an HDR scan will pretty much eliminate the noise from the scanner's sensor, by pumping more light to it, and creating an image well above it's noise floor.