There's a good reason why the heroes' new a billion dollar earner), the MCU is set to wrap up the 22-film arc it's been exploring since 2008's Iron Man.
Directors Joe and Anthony Russo and writers Christopher Markus and Stephen McFeely have the privilege and responsibility to stick the landing for the MCU with Endgame. Plot details are tightly kept under wraps, with Disney running a measured marketing campaign - not giving away any clue as to what goes down in the film after the tragic ending of Infinity War. But aside from the confirmed reunion of core six Avengers after their last collective mission in 2015's Avengers: Age of Ultron, the film will also debut a matching suit for the remaining heroes as they avenge the fallen against Thanos, who decimated half of population in the universe. The purpose and origin of the armors are currently unknown, but Feige says that it was important for Marvel Studios to feature them in the Endgame trailers.
Related: Detailed Look at Thanos’ New Endgame Weapon & Armor
Speaking with Ronin), Ant-Man and Captain Marvel:
“We call them the team suits. And we early on decided [revealing them] was a big differentiating factor between [Endgame] and the other films. The Avengers have never had matching outfits before, [so] we thought it was a very intriguing image to see something that made this film feel new.”
“[We had to] make it feel more than just Infinity War II. Because it’s not. Those team suits add something fresh to it. As does Hawkeye, as does Captain Marvel. As does Scott Lang. All of whom were not in Infinity War, hence Scott Lang and Hawkeye being revealed in that first trailer, and Captain Marvel in the next one.
As previously mentioned, the origins and purpose of the suits are still a mystery at this point, but many are convinced that they will be used to Ant-Man & the Wasp (when he saved Janet van Dyne from the alternate dimension). It's no secret that the Quantum Realm will factor in the film, perhaps hand-in-hand with the concept of time travel. And with both the miniature Quantum Tunnel and Pym's lab in the Avengers' possession during the events of Endgame through Scott, it's almost certain that fans will see them descend the alternate dimension.
The MCU's Avengers have never been known for wearing matching outfits. Each hero wears their respective suit, which helps in establishing individual branding for them. Considering that their assembly in the MCU is out of necessity (with most of them initially reluctant in ing), it makes sense that they never had uniforms - although Tony Stark tinkered on their separate garbs and weapons. Aside from being an immediate distinction between Avengers: Endgame and its predecessors, seeing the whole squad in the matching suits also sends the message of a more united front. And considering what they have been through and what lies ahead for them, they need to stick together now more than ever.
More: All The Avengers: Endgame Quantum Realm Clues (So Far)
Source: iO9