Don't hold your breath. Personally, have not used Synology SS, but guessing it's a re-hash of the NUUO software/GUI. As a NUUO Systems Integrator notice allot of similarity. The Synology supported camera list seems virtually identical to NUUO's. So, if NUUO doesn't support it, it likely won't happen since GV and NUUO are competitors in the NVR world. If a camera is ONVIF certified, there's a slim chance it could work unofficially. It's unfortunate since I too have a couple GV's that would like supported w/ Synology.
A crude work-around Synology could use is to support cameras that can utilize RTSP streaming protocol. Virtually all newer cameras do. Of course, that would exclude certain features like PTZ, de-warping, presets, etc, but at least the video/audio content is available for processing & backup. Also, utilizing the RTSP format would not require a licensing fee.