Spoilers ahead for Episode 2 of Supernatural Season 14, called "Gods and Monsters."
Supernatural knows how to end its seasons on killer cliffhangers, and Season 13 ended on a doozy. As part of the effort to take out Lucifer once and for all, Dean became vessel to the archangel Michael. While Dean as Michael was indeed able to get rid of Lucifer, Michael didn't vacate Dean when he was supposed to, and Season 13 ended with Dean poised to act as the villain while containing Michael. Well, "Gods and Monsters" delivered a huge and unexpected Michael twist that should definitely be temporary.
Here's how it happened. Michael spent most of the episode in Duluth, just as Sister Jo had told Sam and Co. While they prepared to try to capture Michael and free Dean, Michael was busy burning out vampires, making deals with werewolves, and setting traps. Castiel couldn't come along on the mission to Duluth, and both Jack and the de-Lucifer-ed Nick stayed behind as well. It was down to Sam, Mary, and Bobby to get their hands on the archangel.
The good guys seemed to catch a break when they caught a vampire girl on camera and tracked her down. She had a horrifying story to tell, sharing that Michael was killing off vamps after seeming to experiment with them. She managed to escape and drop the news on the three hunters. Fortunately for her, they didn't go ahead and kill her. Instead, they used her info to make a move. She died shortly after they left, but at least Bobby didn't machete her to death. Yay?
Unfortunately for them, they made their move according to Michael's plan. When they showed up at his last known location, they were mobbed by werewolves Michael had won over to his cause, and they weren't any normal werewolves. The usual tricks to kill them weren't working, with even silver bullets failing. The good news is that even these augmented werewolves can't survive being decapitated, but werewolves that can survive silver are a bad sign of what Michael can do.
The good guys won the fight, and they were shocked to see Dean stumble out of the shadows. After Dean dropped a "Sammy" and seemed to express genuine fear and confusion, Sam and Co. accepted that he was not Michael pretending to have vacated Dean. He had no idea why Michael had left him, but he was effectively Michael-less.
Now, on the one hand, it's very good for Dean and his loved ones that he's no longer occupied by an archangel determined to make deals with monsters to enslave the human race. Sam and Nick weren't exactly changed for the better after being stuck with an archangel for significant portions of time, and Nick may not be able to ever entirely shake off Lucifer's influence. If Dean was inhabited by Michael for long, he could have been permanently damaged. Huzzah for the good guys that they got Dean back!
On the other hand, for those of us watching from home... well, it may not be so good for us that Dean has already been de-Michael-ed. After spending months of hiatus expecting Dean to kinda sorta be the primary antagonist of at least a chunk of Season 14, losing Dean as Michael's vessel in only the second episode is disappointing. This is similar to what happened back in Season 10 when Dean's arc as a demon was cut short after only three episodes.
Let's face it: Supernatural is long in the tooth by TV standards now that it's in fourteenth season. While running for such a long time has given Supernatural a rich history and developed the relationships between the central characters in some compelling ways, the show does need to find ways to reinvent itself as time passes, and there are only so many times the Winchesters can stop the apocalypse. Using Dean as vessel to the primary villain of the season would have required Supernatural to reinvent in a good way.
Dean as Michael's vessel gave a valid reason for the characters not to take Michael down permanently. As much as they're willing to sacrifice just about anything (certainly including their own lives), these guys aren't the best at sacrificing each other. Sam was just wishing he'd thought of dealing with a demon to get info on Dean in the previous episode, and Castiel explicitly said to Jack in "Gods and Monsters" they they couldn't kill Michael because it would mean killing Dean. Mary isn't likely to let him die.
For a show that can't kill off its villain in the first couple episodes, a valid reason for the heroes not to kill him is quite important. We wouldn't have to wonder why the characters or the show keep letting Michael get away for as long as he was in Dean's body. Sure, Jack was on board with letting Dean die if it meant killing Michael, but nobody else would be on board at this point.
Jensen Ackles also looked like he was having a great time flexing his acting muscles as Michael. For a guy who has spent more than a decade playing a hero, he's pretty great at playing evil. To lose Ackles as Michael after only two episodes would be a shame, especially after all signs seemed to point toward Ackles being isolated from the rest of the cast because of Dean's status as a vessel.
Hopefully showrunner Andrew Dabb's comments about Jensen Ackles being missing for episodes of Season 14 mean that Michael will be jumping back into his Winchester vessel and not that fans got their hopes up for Dean the villain over hiatus. Michael certainly isn't done as the villain of Season 14, even though "Gods and Monsters" indicated that the Winchesters should also keep an eye on Nick on top of Michael and all their other regular monsters. Perhaps Dean's Michael-less status will change.
Obviously I'm not suggesting that Michael remain in Dean for however much longer the series runs on The CW, especially since it seems like there's something supernatural at work to keep the show on the air and delivering for fans indefinitely. Dean was always going to be freed of Michael at some point in Season 14. My fingers are just crossed that Supernatural will change the twist that saw Michael leave Dean and put the two back together for a bit longer.
If anything, a temporarily free Dean could heighten the drama for when he would be back as Michael's vessel. As Jack said in "Gods and Monsters," Dean would totally want to be killed if that was the way to kill Michael. Dean could certainly tell his friends and family that he'd want them to take him out to take down Michael, and that could brew more conflict.