still-untitled Avengers movie is set to bring over ten years' worth of integrated storytelling to a close.
Whatever form the combined heroes' victory over Thanos takes - and it is assumed they will defeat him, if not use his assistance in fighting some new, even more menacing villain - it's safe to believe that many characters will not be returning afterward. Whether it be by death, retirement or a simple lack of necessity, the MCU will be looking streamline itself going into Phase 4 before it becomes too large and unwieldy to control. Kevin Feige has gone on record to say that he believes Marvel will be sticking to releasing only three films a year, and with so many characters to work with, not everyone can continue to be in the spotlight.
Related: Avengers 4: Every Update You Need To Know
The MCU actors who have helped build this monumental cinematic undertaking, step by step, are also people who should be free to do other things with their lives, regardless of how much they enjoy working with Marvel. It's easy to understand that an actor wouldn't want to be playing one role for the rest of their lives (or even another few years), so fans will sadly be saying goodbye to a fair few of them. Avengers 4 represents the best way to do so, potentially being the most epic and finale-esque capstone to the entire MCU so far.
Iron Man (& Pepper Potts)
Robert Downey Jr's contract is once again up with the release of Avengers 4, and considering that appearances in Captain America: Civil War and Spider-Man: Homecoming were carried out on a rolling basis, if Tony Stark himself chooses to return afterward, it'll be on his . Currently, that seems rather unlikely, with every piece of foreshadowing suggest Avengers 4 will see the man-in-a-can nobly give his life for his teammates and the entire world. There can be no more a fitting end for the man who started it all.
With Tony going, Pepper Potts (Gwyneth Paltrow) likely won't be far behind. The only thing potentially keeping her around is adopting the Shuri.
One Iron Man-related character set to return in the future is Happy Hogan, with Jon Favreau spotted on the set of Spider-Man: Far From Home.
Read More: Every New Iron Man Armor Rumored For Avengers 4 (So Far)
Captain America (& Peggy Carter)
Chris Evans hasn't been shy about his intentions to leave the MCU with Avengers 4. He first teased Sam Wilson, not Bucky Barnes).
With Captain America going, so too surely does Peggy Carter (Hayley Atwell). Although the character sadly ed away in Captain America: Civil War, she's been a constant presence in various time periods of the MCU, with rumors that ABC show is resurrected.
Thanos
He may not be a hero, but you can certainly bet on Thanos not making it out of Avengers 4 too. He's been the big bad of the MCU teased since ending on the Mad Titan's victory, that means the next movie surely has to be his defeat.
Related: What If Avengers 4's Villain Isn't Thanos? Predicting A Shocking Marvel Twist
How is something even Avengers 4 leaks haven't teased, although we can make some strong assumptions about his fate. While in the comics, Thanos has normally lived past his atrocities, in one famous case becoming a farmer, that feels like too light a handling for the decade-long story of the MCU. Even if he does somehow survive the events of Avengers 4, Marvel's going to want to move past Josh Brolin's purple maniac, so Thanos is sure to bid the universe farewell.
Page 2 of 2: Secondary MCU Characters Unlikely To Make It Out Of Avengers 4
Quicksilver
Regardless of Pietro Maximoff's valiant sacrifice for Hawkeye and an unnamed Sokovian child in Avengers: Age of Ultron, fandom had never felt that it was truly the end for the character. After all, the Infinity Stones - which with all their combined power undoubtedly have the ability to bring the dead back to life - are still floating around almost four years later. Not to mention, Quicksilver was such an under-utilized character, definitely in contrast to twin sister Wanda Maximoff (Elisabeth Olsen). Sketchy Eastern-European accent and comparisons to the X-Men version aside, the MCU's Quicksilver has his fans, and many more would like to see the character reunited with his sister for emotional catharsis and a deserved second appearance on the big screen.
Rumors have abounded that Quicksilver may be back in Avengers 4, opening up the possibility that he will find himself brought back to life akin to the snap victims. However, that may be wishful thinking. Actor Aaron Taylor-Johnson has recently gone on the record as saying that another appearance for Marvel Studios is "not a conversation" that's being had right now. Whether he's employing the time-honored MCU actor's traditional tactics of evasiveness for the sake of protecting spoilers or actually will not be returning, the lack of word makes it seem any appearance would be a flashback, rather than a future tease.
Read More: Avengers 4 Should Bring Back the MCU's Quicksilver
Crossbones
Although Crossbones met an untimely end at the opening of Captain America: Civil War, actor Frank Grillo has spilled the beans and revealed he will return in a "flashback" in next year's Avengers 4. The set photos revealing an aged Tony Stark and seemingly-present day Scott Lang being present at The Avengers' Battle of New York suggest time travel of some sort as a certainty, so Grillo's quote holds up.
What's not so certain is Crossbones' return after Avengers 4. With the character firmly vaporized and his next appearance touted as a flashback, it's unlikely that Marvel is planning a long-term resurrection.
Read More: Could Crossbones Have Survived Captain America: Civil War?
Drax
Following Guardians of the Galaxy Vol. 3 without him, tweeting that it was "nauseating to work for someone who'd empower a smear campaign by fascists".
Of course, he's still The Eternals filling the cosmic hole in 2020, that may be a long way off or retooled. As such, Avengers 4 could well be Bautista's somewhat unintended swansong for the MCU.
