Avengers 4 is already among the most anticipated films of 2019, promising to solve not only the cliffhanger left by Infinity War, but the entire last decade of the Marvel films. The public has not yet seen a trailer, but there are reasons to believe that that can change soon.
The ArcLight Hollywood will have a special screening of the film tomorrow night, on November 28, which will be followed by a question and answer session of the co-directors, the Russo brothers. The original Infinity War trailer debuted on November 29. Marvel will publish a comic "Prelude" on December 5, before which we expect the title of Avengers 4 to be revealed. In addition, we already know that the Avengers 4 trailer will arrive this year.
By putting all the pieces together, it seems reasonably likely that tomorrow's ArcLight event will be premiered for the small audience that will attend. Then, the full trailer could fall on the Internet later in the evening or the next day: the first anniversary of the last trailer. And it would pave the way for the revelation of the title in time for the comic.
The title of Avengers 4 has been kept secret, although the Russos have dropped cryptic clues. So far, the most likely seems to be Avengers: End Game, a reference to a line (and the main plot point) of Doctor Strange in Infinity War.
We hope that the Avengers 4 conclude the Thanos arc of the Marvel cinematographic universe. First mocked in a sequence of post-credits in the original movie of The Avengers, Thanos has not interacted with the MCU heroes directly until Infinity War. In that film he revealed his complete plan for the Infinity Gauntlet: to obtain the power to extinguish all life in the galaxy by sheer will and a snap of his fingers. The resulting events killed many well-established characters in the MCU, leaving a suspenseful end to Avengers 4.
Before it arrives, however, we will receive a dose of reinforcements. In a sequence of post-credits in Infinity War, Nick Fury calls a last contingency plan: Captain Marvel. The implication is that she will be the trump card of the heroes, and we will see exactly why, and where she has been all this time, in her own independent film on March 8, 2019. Avengers 4 will follow on May 3. .