There are many rumors circulating about "Supernatural" ending with Season 14. There is no confirmation that this is the truth, despite publications claiming that it is. This is a rumor that has spread since Jared Padalecki shared that the next milestone for the show was the 300th episode. Jensen Ackles later confirmed that this was just the next milestone and not where the show would end.
'Supernatural' will continue until the stars are done
The CW looks set to continue to renew "Supernatural" until the two main stars are done with it. This means Padalecki and Ackles have full control over when to call it a day.
However, they have not shown any signs of wanting to quit. Why would they when they have a secure job for the foreseeable to support their families? They are also happy with the way things are running behind the scenes.
The claims that "Supernatural" season 14 is the end are completely fabricated. Right now J2, as they are nicknamed by fans, have no plans on actually stopping with the season. They will continue the show while they are happy with it and there are more stories to tell for the Winchesters. Of course, they may decide at the 300th episode that they've had enough, but right now that is simply another milestone to reach.
The stars do have an end in mind
According to Ackles, there is an ending in mind.
The team has discussed a potential ending episode number, which would allow the Winchesters to go out while they are still on top. The actor never shared what that episode number would be, but he made a point in saying that the 300th episode comment was definitely just Padalecki discussing the next milestone to reach.
Nobody knows for certain, so any publication claiming that it does is just stirring rumors to scare and annoy fans.
The CW doesn't have a plan for ending the series yet. The longest-running series on the network is still gaining fans, even gaining new fans considering it has run for longer than a decade.
Mark Sheppard is officially done with the series
The only change that "Supernatural" will see moving forward is no Mark Sheppard. It's unclear whether Crowley will return, but it won't be in the form of Sheppard.
There are many rumors as to why he has gone, but most fans believe that it is linked to Creation Ent. conventions. Sheppard had made a point that he will never do another Creation convention again, yet will consider doing others if he's asked.
"Supernatural" season 14 is not officially the end. At least not yet. Don't believe the rumors, whoever writes them, until Padalecki, Ackles, or The CW officially confirm that the show is over.