Here is a view of the dual bracket, from Kodak’s website.
What is strange about the picture above is that there is no clear means of attaching the cameras to the bracket (the bottom of the SP360 is flat and covers the battery compartment). Moreover, it appears to be only a CG render.
The 3DR photo shows a slightly different version of the dual bracket (it also shows that there is no onboard camera when using the dual camera bracket). It appears from this photo that the dual bracket works with the SP360’s “standard housing-B”.
At first glance it means that the dual bracket won’t work with other cameras, because the other cameras won’t fit in the standard housing-B. However, the standard housing-B appears to use a mount that looks similar to a GoPro mount. If so, it might mean that cameras that have a GoPro-compatible mount can also be attached to the dual camera bracket.