User blog comment:MystiTrainer/The Future of the MCU/@comment-25179360-20180422030514

I'm not sure if Iron Man needs a "replacement" so to speak. Black Panther and Doctor Strange might be the closest thing we get. My reasoning is that Marvel wants to completely revamp the status quo after Infinity War, and bring The Avengers to new heights by remaking the team with fresh blood. Retiring Captain America, Iron Man, and Thor just to have someone else take up the mantle would kind of cheapen their sacrifice and could lead to fatigue seeing the same heroes leading everything for another ten years.

I could see Shuri becoming someone very similar Riri Williams in the future though. She does end up becoming Black Panther in the comics. Maybe in the future Shuri makes some sort of Black Panther-Iron Heart amalgamation suit?