With this story taking place throughout the course of well over a decade, audiences have had plenty of time to grow attached to Sebastian Stan's depiction of Bucky Barnes, with the character being one of the MCU's most popular. That said, this may not be enough to save Bucky from a dire fate - with one grim theory about Avengers: Doomsday's story seeming more likely because of Stan's real-world filmography.
Sebastian Stan's Upcoming Movies Make The Theory Bucky Dies In Avengers: Doomsday Look Far More Likely
The next few months and years bode well for Sebastian Stan fans, since a wide selection of movies involving the actor are on the horizon. Notably, the majority of these films currently appear set to release after Avengers: Doomsday, with The Batman: Part 2, Burning Rainbow Farm, Impunity, Reckless, Frankenstein In Romania and Ruins - which will see Stan appear alongside fellow MCU star Vanessa Kirby - impending for the actor.
While Sebastian Stan has been involved in an assortment of other projects throughout his time in the MCU, the number of movies set to release in the coming years featuring the actor suggest Stan's schedule is in popular demand. This would theoretically make any future appearances in future MCU releases far more difficult, suggesting that these projects may involve the actor because he isn't contracted to appear in anything after Avengers: Doomsday.
Theories that Bucky dies in Avengers: Doomsday in order to add more emotional weight to the movie and continue the MCU's penchant for dramatic deaths were already rampant looking at the character's arc in the franchise alone, so this real-world roster of upcoming Sebastian Stan movies appears to only make Bucky's fate look all the more likely,
Bucky May Be The Only MCU Hero The Franchise Can Currently Kill Off
The MCU only has a relatively small number of major heroes who've been present in the franchise for most of its run thus far, and the majority of these figures are characters the Marvel movie world may be hesitant to lose given the aftermath of the loss of Black Widow, Captain America and Iron Man in the final chapters of the Infinity Saga, which is arguably still something the franchise is course correcting from.
Given Hulk is one of the MCU characters fans complain about not having gotten the limelight enough the most, it stands to reason he would logistically be off the proverbial chopping block. While Thor could be a solid candidate for such a fate, the fact he's the sole remaining hero from the original Avengers with his own MCU movie series may also mean he isn't someone the franchise would risk killing off right now, especially given Doomsday has already brought back Chris Evans and Robert Downey Jr. for the next Avengers installment after Avengers: Endgame.
As such, Bucky may tragically be the only candidate who is a staple MCU character with a well-established history and plenty of fans, and a figure with a story that could potentially end at Doomsday without losing too much - since The Falcon & The Winter Soldier and Thunderbolts* cement the final pieces of Bucky's healing journey of sorts.
That said, given just how beloved Barnes has been ever since his introduction into the MCU, there's also plenty of reason to hope he survives for further chapters of the franchise's story, particularly since the formation of the New Avengers could be a major starting point for a new arc for the character as well. However, given all the other context around Bucky's current MCU story, it wouldn't be a surprise if we're saying goodbye to yet another iconic Marvel hero very soon.
TV Show(s)
Agents of S.H.I.E.L.D., Agent Carter, Inhumans, WandaVision, The Falcon and the Winter Soldier, Loki, What If...?, Hawkeye, Moon Knight, Ms. Marvel, She-Hulk: Attorney at Law, Secret Invasion, Marvel's Echo, Agatha All Along, Ironheart, Daredevil: Born Again, Your Friendly Neighborhood Spider-Man