A notice for the small update (3.32MB) mentions that the edge screen was the only part of the phone affected by it. And to avoid the use of your precious data, it is suggested that you be connected to a Wi-Fi network while downloading and installing the update, which has been characterized as being "urgent" by Samsung. The manufacturer goes on to suggest that the task be completed to "prevent errors from occurring."
One possibility is that the update adds support for certain apps which can be used along the curved edge of the handset's touch screen. And with some complaining that the edge is so sensitive that they accidentally activate apps when merely holding the device in their hands, it is possible that the update has something to do with that issue.
If your Galaxy S7 edge is already in your possession, keep an eye peeled for this urgent update. It shouldn't take up that much of your day to make sure that the edge screen on your unit is properly working.