Speaking to Vanity Fair, The Russo Brothers told that Jon Favreau called them during Avengers: Endgame filming and beg them to reconsider.
The Russo Brothers told “Part of the pressure [not to kill Tony Stark] came from Jon Favreau, who called us up after he read the script… and said to us, ‘Are you really going to kill Iron Man?’” revealed Anthony Russo.
“He did. Yeah,” added Joe Russo. “And I remember pacing on the corner of a stage on the phone with Favreau trying to talk him off a ledge.”
“Everyone knew this was going to be the end of Tony Stark,” said McFeely.
“We had the opportunity to give him the perfect retirement life, within the movie,” added Markus. “[He already got that]. That’s the life he’s been striving for. Are he and Pepper going to get together? Yes. They got married, they had a kid, it was great. It’s a good death. It doesn’t feel like a tragedy. It feels like a heroic, finished life.”
Avengers: Endgame grossed $2.798 billion worldwide, surpassing Infinity War’s entire theatrical run in just eleven days and breaking numerous box office records.