Warning, this article contains spoilers for Avengers: Endgame.
The cosmos is full of enemies and it seems like our Avengers have already done their part in pissing off almost all of them. To face further challenges, don’t you feel that we might the full strength of the Avengers? We definitely would!
But unfortunately, we don’t have them. We lost three of our original 6 Avengers. One sacrificed her life to retrieve the soul stone, one decided to live off his life and go to retirement (Totally deserved). While one of them gave his life away to save the entire cosmos: Our dear Tony Stark. The snap killed him but saved everyone. The wielder of all the infinity stones, genius, billionaire, playboy, philanthropist, sacrificed himself for the greater good.
Tony Stark’s is 100% dead and there’s pretty much nothing we can do about it. So what if we need Tony again? or His extraordinarily genius brain? We might not have Tony but there’s a chance we might have his brain.
Yes, we have a theory that it is possible that Tony might’ve transferred his consciousness into a computer. Mr. Stark always thought two steps ahead of everyone and acted accordingly. Like with the infinity gauntlet, he created the infinity gauntlet in such a way that the stones would come off if he wishes them to. Saved the universe? Totally!
Tony Stark was a master engineer. He had the technology, money, brains, resources to build an entire computer system with his mind uploaded into as an Artifical Intelligence user interface. Not to forget he had already built two AI’s before. JARVIS and F.R.I.D.A.Y.
FACT THAT SUPPORT THIS THEORY:
 ARNIM ZOLA:
To run your memory, Arnim Zola is the top scientist of HYDRA. His first appearance was in Captain America: The First Avenger. Then we see the plan set in motion by him in Captain America: The Winter Soldier.
In Captain America: The Winter Soldier, Zola created a new HYDRA within SHIELD after he was recruited by SHIELD. “After the war, S.H.I.E.L.D. was founded, and I was recruited. The new HYDRA grew, a beautiful parasite, inside S.H.I.E.L.D.”―Arnim Zola
There, with the resources from SHIELD, he secretly built an Artifical Intelligence in which he uploaded his consciousness. So, even though his body died in 1972, his mind continued to live in Cyberspace. You know how it goes from there, his plans are still in motion and his consciousness is still alive well until it was destroyed.
If Arnim Zola could do it in the 1960s, then Tony can easily do it with his latest technology of this generation. Come to think of it, all those 5 years in the cabin and even before that, he had plenty of time to transfer his consciousness into an AI. He might’ve also had!
The Marvel Cinematic Universe and our Iron man are anything but predictable! We only have theories which might make sense. To find out if we get to hear more of Mr. Stark is only a question that future can answer.