The scene in question would have likely taken place on Ebony Maw’s spaceship where he was holding Doctor Strange prisoner.
With the upcoming Doctor Strange film introducing the multiverse to the MCU, which carries many alternate versions of familiar characters, fans may very well get to see a version of Stephen Strange who became Iron Man, or a Tony Stark who became the Sorcerer Supreme.
The Iron Man armor has actually been worn by other major characters.
Iron Man and Spider-Man snuck onto the ship to rescue Strange, managing to blast the incredibly powerful Ebony Maw into space before he had time to counter their plan.