Avengers: Endgame writers Christopher Markus and Stephen McFeely admit that not everyone agrees with them on Captain America's fate in the movie. One of the many tasks Endgame set out to accomplish was to provide a satisfying resolution to the stories of many of the original Phase 1 Avengers, sending iconic characters off on a high note. In Steve Rogers' case, he was able to go back and have his long-awaited dance with Peggy Carter, returning to the present as a peaceful old man who lived a full life. For many, this was the perfect conclusion to Steve's arc.
The image of Steve and Peggy dancing to "It's Been a Long, Long Time" is extremely cathartic, yet the time travel shenanigans of Endgame raised some big questions that continue to be debated to this day. Surprisingly, the film's creative team doesn't see eye-to-eye on the way things turned out. Endgamedirectors Joe and Anthony Russo maintain Steve went to an alternate dimension and then came back to the prime timeline, while Markus and McFeely believe Steve was Peggy's husband in the prime timeline all along. The writers understand not everyone at Marvel agrees with their interpretation.

In an interview with Canada.com, McFeely once again touched on this subject, admitting he's unsure if Marvel considers their interpretation official canon:

It depends on what story Marvel wants to tell going forward. I don’t know if Marvel wants to tell any more Captain America stories or if Chris (Evans) is up for it. Do they want to tell an alternate timeline story? Chris and I are partial to the idea that Steve is part of a strange, unique time-loop where he has always been there. The husband that you very purposefully did not see at Peggy’s bedside in Winter Soldier is Chris’ Steve. We have always thought that he was her husband. The movies you have been watching follow a line where he always goes back. To be fair, not everyone agrees with us. I don’t even know if Marvel agrees with us. But that’s what we think.

It's surprising that Endgame's writers and directors have varying opinions on what happened to Steve Rogers. The finale of a key character's story arc seems like something that would have to be agreed upon by the principal creative voices of the film. There's nothing wrong with a little ambiguity sometimes (see: the ending of Inception and what really matters in the final scene), but this is something that can significantly impact MCU canon moving forward. Granted, Marvel isn't averse to retconning certain aspects or plot points (Peter Parker in Iron Man 2 is a good example), but there probably should have been some discussions during pre-production to determine with some level of certainty the nature of Steve's journey back to the 1940s. Endgame's time travel was confusing enough because Marvel changed the rules. It would have been nice to have a straightforward response to Captain America's fate.
What'll be interesting to see is if Marvel opts to revisit this at a later point or just leave it be. It might be better (and safer) to go with the latter. Regardless of which interpretation one sides with, it's universally agreed upon Steve got the ending he deserved, and to bring Chris Evans back for another project would run the risk of mucking that up. It's possible Marvel could come up with a compelling story to lure Evans back (after all, Natalie Portman is returning for Thor: Love and Thunder), but Evans is looking forward to beginning a new chapter of his career right now and Marvel has a lot of exciting things on deck. Perhaps Marvel should let fans believe what they want about Endgame and not definitively canonize one explanation over the other.

Source: Canada.com
  • Black Widow (2020) release date: May 01, 2020
  • Eternals (2020) release date: Nov 06, 2020
  • Doctor Strange in the Multiverse of Madness (2021) release date: May 07, 2021
  • Thor: Love and Thunder (2021) release date: Nov 05, 2021
  • Shang-Chi and the Legend of the Ten Rings (2021) release date: Feb 12, 2021