This event could involve significant recasting for characters like Tony Stark, or even lead to the inclusion of the Fantastic Four in the Marvel Cinematic Universe.
Numerous fan theories have already suggested the possibility that fan-favorite Fantastic Four characters such as Doctor Doom could potentially appear (or at least be hinted at) in Infinity War, so anything’s possible at this point.
The implications of this moment could have the potential to reach much further than a high body count as well.
If Thanos’ goal is the balance the universe and even it out in a way that he sees fit, then we could potentially see quite a bit of retconning occur as we move out of Phase 3 and into Phase 4.