You're better to ask in the developer section (switch using the drop down on the top right which says Community). You may not get an answer though - my understanding it this happens for apps/games which either have content Oculus don't want on the store or are too low quality.
From Oculus this afternoon (Still confused about interpreting it)
First and foremost, thank you for your continued work on your title. We are always looking for fresh and innovative titles to bolster our platform. Oculus continues to monitor user metrics for our keys-only apps, and any titles that show outstanding user adoption, game play time, etc. are reviewed regularly for conversion into our Oculus Store.
With this in mind, our Content Review Team has decided to keep Dragon Flight as a keys-only title at this time.
