Because this is a generic system-generated name for a personal media file, there is no public "write-up" or official documentation associated with it. To provide a helpful summary or description, I would Understanding the Filename : Indicates the file is a video.
: The date the file was saved or sent (September 23, 2017). WA : Stands for WhatsApp.
The filename follows the standard naming convention for a video file received via WhatsApp on September 23, 2017.