While fans eagerly await the return of some long-absent MCU characters, not all of them are likely to be back. The casting announcement for Avengers: Doomsday revealed a massive roster of heroes, but also left out some notable names. Now come the questions about when we'll see these missing characters again.
With the post-Avengers: Endgame MCU being something of a mess, there have been some high-profile characters pushed to the side for too long, as well as some new characters who have yet to make a real impression. While the wait is long, some of these heroes are guaranteed to be back, while others are destined to become unfulfilled footnotes in the MCU.

Will return: Doctor Strange
Last live-action appearance: Doctor Strange in the Multiverse of Madness (2022)
Doctor Strange is one of the most surprising names left off the Avengers: Doomsday cast announcement. Given his ties to the multiverse, he seems like an obvious inclusion. Regardless of whether he ends up appearing or not, we have not seen the last of Benedict Cumberbatch's sorcerer.
Strange is a wonderfully unique hero in the MCU, with plenty of potential still left. Surprisingly, he has not been made more central in the cinematic universe, but he is obviously still a key part. Fans can expect at least one more solo Doctor Strange adventure, along with any team-up movies he appears in.

Gone for good: Clea
Last live-action appearance: Doctor Strange in the Multiverse of Madness (2022)
It used to be that a new character was teased in an MCU post-credit scene, leading to their full appearance in the franchise's next movie. Those days are done as the MCU has teased countless characters with seemingly no idea of when they will show up again. Such is the case with Clea and her cameo at the end of Doctor Strange in the Multiverse of Madness.
Fans have been waiting to see this Doctor Strange character appear for quite some time, and the casting of Oscar winner Charlize Theron is impressive. But her role is handled so awkwardly, and so much time has already past with no new Doctor Strange movie on the horizon, it is unlikely there will actually be a payoff.

Will return: Moon Knight
Last live-action appearance: Moon Knight (2022)
The MCU Disney+ shows have struggled greatly when it comes to introducing new characters. However, while Moon Knight's solo series was not a great success, there is still too much excitement around this character and his future to squander it. Especially with Oscar Isaac in the lead role.
Moon Knight may not be a household name, but Isaac has helped to raise interest in the fascinating character. It is a difficult matter of figuring out where the character can fit into the universe going forward. The wisest choice would be to leave behind the television format and finally enter the movie side of the MCU.

Gone for good: Black Knight
Last live-action appearance: Eternals (2021)
Eternals is a movie filled with characters and hanging storylines that seem unlikely to ever get resolved. However, Black Knight is an especially unfortunate casualty of that movie's underperformance, as his story barely had time to begin. Sadly, Dane Whitman's transformation into the medieval-esque hero is not looking good.
The fun casting of Kit Harrington immediately raised interest in this obscure character. Eternals also began awkwardly planting the seeds for his origin story in the background. With very little of that registering with fans, it feels like an easy one for the MCU just to let go of and pretend it didn't happen.

Will return: Kate Bishop
Last live-action appearance: The Marvels (2023)
Out of all the new MCU characters introduced on a Disney+ series, Kate Bishop seems to have been the most successful. Hailee Steinfeld's winning performance immediately made her a lovable addition to the cinematic universe. Fans were even on board with her taking over the mantle of one of the original Avengers.
There were clearly plans for Kate's future in the MCU as the post-credit scene of The Marvels teased her inclusion in a Young Avengers team-up. That seems less likely now, but there are still plenty of places Kate would fit in. Now that Jeremy Renner's MCU future seems unclear, we might be in need of a new Hawkeye.

Gone for good: She-Hulk
Last live-action appearance: She-Hulk: Attorney at Law (2022)
While not everyone was a fan, She-Hulk was an MCU show that really embraced the fact that it was on the small screen. It served as a sitcom that was set within this exciting superhero world, and that made for some really fun moments. To cap it off, Tatiana Maslany was exceptional in the lead role.
However, the style of She-Hulk makes it hard to fit her into the overall MCU. The series constantly broke the fourth wall, eventually commenting on the MCU itself in a very bold way. After that point, it would be hard to see the character fighting alongside the other heroes against Doctor Doom and take it seriously.

Will return: Captain Marvel
Last live-action appearance: The Marvels (2023)
Captain Marvel seemed like the hero who was best poised to lead the MCU after Iron Man and Captain America were gone. However, they never quite figured out how best to use her. This was partially because Captain Marvel ran into a similar issue Superman deals with, as she is too powerful to be interesting.
We have yet to see great use of Captain Marvel in the MCU, but that doesn't mean they should stop trying. Some have suggested the disappointment of The Marvels marked the end of the character, but Marvel would be foolish to let a huge character like this and an Oscar winner like Brie Larson go unused.

Gone for good: Hercules
Last live-action appearance: Thor: Love and Thunder (2022)
Brett Goldstein's casting as Hercules in the MCU is one of the best in recent memory, so it is a shame that a few seconds of screen time and two words of dialogue are probably all he's going to get. Hercules appears in a post-credit scene of Thor: Love and Thunder, teasing an eventual showdown with Thor that is never going to happen.
There have been strong hints that Avengers: Doomsday will be the final appearance of Chris Hemsworth's Thor. This leaves Hercules in a strange purgatory with no clear place to go next. It is another unfortunate example of the MCU teasing something exciting without any plans to pay it off.

Will return: Kang the Conquerer
Last live-action appearance: Loki (2023)
Kang is a character who was always destined to be a big-bad in the MCU. However, he is also a character who has faced a lot of uphill battles in the cinematic universe. After a disappointing introduction, the messiness of the multiverse, and the controversy of Jonathan Majors, the MCU cut its losses and moved on to Doctor Doom.
It was an awkward pivot for a character they spent a long time building up. However, it would be shocking if Kang didn't return at some point to continue his story. Despite the controversy, Kang is a character who is uniquely easy to recast, and the right actor can help set him back on the right path.
