Well, according to Supernatural showrunner Andrew Dabb, Season 15 will showcase some of those other worlds and another Dean.
All bets are off for Supernatural now that it’s in its final season with none other than God as the big bad.
God revealed back in Season 14 that Sam and Dean were his favorites of the many pairs of Winchester brothers in the many worlds he’d created (before Sam shot him, anyway), which suggests that God had messed with all the others similarly to how he messed with our Sam and Dean.