A Supernatural reboot seems inevitable. Here is how the show can return while still honoring years of canon.
Supernatural gave Sam and Dean Winchester a final ending with season 15. However, death has never stuck on this show, and the odds of the show getting a reboot are surprisingly good. It helps that the series has set up countless ways to defy death over its 15 season-run, and that gives the writers room to get creative about how they want to start a new season. So, here are 10 ways that Supernatural can be rebooted without changing its current canon in order from least to most likely.
At first, Djinns were creatures that trapped victims in an ideal world, but that changed in season 6, where Dean is poisoned by a Djinn that makes him see nightmares in episode 1 "Exile on Main St." The ending section could stay canon and allow for a reboot if, instead of happening in reality, it was a dream created by Djinn poison. While it might be a bit unsatisfying as an option, this choice does allow for a clean transition from the ending into a new season.
As unlikely as this would be, stranger things have happened in Supernatural. Taking this route gives the showrunners a unique benefit, as well, since it kicks off a new plot right away. If the Dean who was impaled was a Shifter, then that means the real Dean is missing. Additionally, being impaled by a material that isn't silver wouldn't be enough to kill the Shifter. So, Sam would have to deal with the Shifter and find his brother to kick off the reboot.
Parallel universes have already been established in Supernatural, and Chuck (who is God's secret identity hiding on Earth) confirmed that there are countless Sams and Deans across them. This opens up the possibility for the show to switch to a similar Sam and Dean, but ones who weren't in a situation where Dean died in a barn. Of course, the show could take a more radical approach and switch to have the reboot focus on a completely different Sam and Dean, such as those from the HunterCorp universe.