One of the most exciting announcements during Marvel’s Comic-Con Phase 4 presentation was the confirmation of an official MCU-based What If…? animated series featuring actual MCU actors voicing their iconic movie characters.
Airing Summer 2021 on Disney+, What If…? is a new animated series based on Marvel’s classic series of “alternative history” comics that started in the ’70s and explored how things might have played out if key moments in the Marvel timeline never happened. Some famous stories/examples were “What if Wolverine Had Killed The Hulk?,” “What if Spider-Man Had Never Become a Crimefighter?,” and — notably — “What if Jane Foster Had Found the Hammer of Thor?”
Source: IGN.com Marvel's What If…?: Every Returning MCU Actor