While I think it's a marketing point for Ford, most people may have a skewed perception of what it is supposed to do. My understanding of how this works is that when a pothole (depression) is detected, it stiffens the damper to the stiffest setting to avoid a full extension. However, there is still some sort feeling/motion into the abnormality as the entire portion of the car is going to drop (laws of physics).
Unfortunately it's hard to test unless you've got another Fusion without pothole detection that you can drive over the same pothole back to back for comparison. I certainly can't say for certain that it doesn't work, but I did expect it to have more of a noticeable difference.