Avengers: Endgame was a massive movie and there was so much for us to take in. Imagine if this 3 hour movie was edited to what we got, then there could be so much lying upon the floors of the editing room. The film ran such a plot that there were multiple possibilities to everything that could have happened. This was a time travel movie and the Avengers literally went back to the previous films of the MCU.
But given that they had ultimately gone to The Avengers, Guardians of the Galaxy, Thor: The Dark World, and perhaps Infinity War (if you count Vormir), we could have actually got a few different sequences if the writers designed the plot a little differently. Christopher Markus and Stephen McFeely were actually iffy to revisit the battle of New York earlier. Markus said:
“We were initially hesitant to go back to the first Avengers because it seemed like we were just pandering and playing the greatest hits. You like that movie? We’re going right back to that movie! And then it really became clear we were overthinking it in terms of what would be the most fun.”
But if they wouldn’t have the Avengers visiting the first movie, then there were a few alternate missions and scenes that they had planned. They said:
“McFeely: We went back to Asgard. But there’s a moment in the MCU, if you’re paying very close attention, where the Aether is there and the Tesseract is in the vault. In that iteration, we were interested in Tony going to Asgard. He had a stealth suit, so he was invisible, and he fought Heimdall, who could see him.
Markus: Thor had long scenes with Natalie Portman. And Morag was hugely complicated.
McFeely: It was underwater! That was clever but it was just too big a set piece. What that didn’t do is allow for Thanos and his daughters to get on the trail at the right moment. So we went back to when Peter Quill was there. And we realized that when you can punch Quill in the face, it’s hilarious. I still think it’s hilarious.
Markus: There were entirely other trips taken. They went to the Triskelion at one point to get the [Tesseract], and then somebody was going to get into a car and drive to Doctor Strange’s house.”
Now as they spoke with Fandango, they gave us a few more details upon Tony and Thor’s mission to Asgard. McFeely said:
“Yeah, our first draft was a version where Tony and Thor go to Asgard, because I like the idea of Tony going, like, in theory going to Asgard and seeing science versus magic, and stuff like that. And then he fought Heimdall, who could of course see him even though Tony had an invisible stealth suit on or something.
And we did that because there is, in Dark World, to get technical about it, during that time when the Reality Stone is there, the Space Stone is also in the vault. So at the end of Dark World you might remember that Volstagg and Sif go to the Collector and pass off the Reality Stone because they don’t want to keep two stones in one place. So that was one attempt at it, and I think Joe Russo read it and he goes, ‘Why aren’t we going to Avengers? It’s only the most exciting movie.’ And so we went yep, let’s do that.”
And that’s how the decision to go to the first Avengers movie was made. Seeing Tony wear an invisible stealth suit would have been awesome though. Well, other than the Avengers, we would have loved to see them revisiting Age of Ultron as that would have brought Ultron back into the game, and perhaps even Quicksilver could have had a chance to see the future he never could. The final battle would have been cool with him in it. But it is what it is, and we are happy with it.