Beginning today, we will start the process of expiring past streams for all Gaming Video Creator accounts. While this change applies to all Gaming Video Creators, some may see it reflected in their Live Dashboard sooner than others as we roll the update out in stages over the next week. We’ve added expiration dates for past streams in the Live Dashboard to help you identify what’s expiring and when.
Please read this important update about your previously-live videos.
So it looks like Facebook Gaming will be copying the Twitch method of keeping previously live vod's on the server for a certain amount of time.