Recently got a Sonnet xMac Pro Server case to put my MacPro6,1 into my rack. I’m getting things fitted into the Thunderbolt expansion housing and noticed this board with a socket on it. The board has power wired from the PSU, but there’s nothing in the manual/product details (even though it’s in the illustrations) that indicate what this connector is or what its intended purpose is. Can anyone enlighten me?

Edit: I just looked up a video of a version of this module with an outer case, for desktop use. Otherwise looks the same inside. It looks like this might provide power to 2 top-rear mounted fans. https://youtu.be/zG4I8q5JbyY?t=285