User blog comment:Twilight Despair 5/New Final Season Idea (Fanmade)/@comment-10603955-20121209014421/@comment-108.225.237.226-20121209090217

Although you are correct that Supernatural is being planned to continue up to a tenth season, there is always a possibility that it could end sooner due to circumtances such as low ratings or Jensen and/or Jared not wanting to continue the series any longer.