Captain America actor Anthony Mackie posts an The Avengers: Doomsday cast will likely be headlined by team leaders such as Anthony Mackie's Captain America and Florence Pugh's Yelena Belova, as suggested by Captain America: Brave New World and Thunderbolts*.
Anthony Mackie shares a video of himself wishing fans "a warm, beautiful, sunny day" from the Avengers: Doomsday set (via Cosmic Circus), which appears to be a remote and snow-covered location. Mackie ends the video by looking around the deserted place with a puzzled look on his face. Check out Mackie's post below:
How Anthony Mackie's Social Media Post Ties To An Avengers: Doomsday Theory
Avengers: Doomsday May Finally Introduce Latveria
It's difficult to pinpoint which MCU location Anthony Mackie's set video is supposed to depict, but the fact that it looks so cold and remote could be a hint that Avengers: Doomsday will visit a region of Latveria. Previous Fantastic Four movies have largely overlooked the fictional Marvel location, but Doctor Doom's MCU debut might finally adapt the villain's home country. Robert Downey Jr.'s Doctor Doom will take center stage in Avengers: Doomsday and Avengers: Secret Wars. If Phase 6 delves into Doom's origins, Latveria is highly likely to make its first appearance sooner rather than later.

The Avengers Accidentally Created Doctor Doom With Avengers: Endgame According To Massive Avengers: Doomsday Theory
A shocking Avengers: Doomsday theory explains how Earth's Mightiest Heroes might have created Doctor Doom by accident in Avengers: Endgame.
A big question surrounding Robert Downey Jr.'s Doctor Doom and Latveria is whether they're going to be introduced in the MCU's main timeline or in a different universe. If they've existed all along on Earth-616, then the Avengers might travel to Latveria before Doctor Doom launches his plan to reshape the multiverse. If both Doctor Doom and Latveria's scenes take place in an alternate timeline, then the Avengers may first have to gain access to multiversal travel before they can pay Doom a visit. Either way, Doctor Doom's Latveria origins may be even more important to his arc than Titan was to Thanos' in Avengers: Infinity War and Avengers: Endgame.
Our Take On Anthony Mackie's Social Media Post
Latveria's Full Reveal Could Be A Huge MCU Event
Latveria has never been adapted properly in live-action, and it has never been mentioned in the MCU. Latveria and Doctor Doom's origins are a mystery at this point, meaning Avengers: Doomsday could make their on-screen debut a huge reveal. After The Fantastic Four: First Steps introduces a stunning, retrofuturistic, alternate-universe New York, the chances of Latveria being a visually striking, fantasy-inspired Eastern European kingdom are high.
Source: Cosmic Circus

Avengers: Doomsday
Cast
- Thor
- Vanessa KirbySue Storm / Invisible Woman
- Johnny Storm / Human Torch
- Ebon Moss-BachrachBen Grimm / The Thing