No. It is not a satnav. I don't know of any dashcams that are a satnav. They are dashcams, designed to take videos of where you are going and are not designed to tell you where to go.
Having said that, there are some satnavs that have a dashcam capability.
Only if you want to know the exact time and location of any incident, and to prove that you were not moving, or how fast you were going at the time etc.
Without GPS you only get a recording of what happened.
With GPS you get the following information as well as the video.
GPS position (This can be played out on a map with the NextBase (and other) software.)