There are quite a few outlets or cheat threads on the Internet claiming to have details on the first Avengers 4 trailer. One of the latest comes from a Russian site, which not only claims to know when we're getting the Avengers 4 trailer, but also what the official title of the movie will be, and the name of the musical track that will be featured in the trailer.
You can check out the post from VK, the Russian social media website, below:
This post states that Avengers 4 is titled Avengers: Annihilation, and that the first trailer will arrive in November. It's also stated that the trailer will use the track "Dust and Light" by Twelve Titans Music, a song fans may recognize as the track used for the Hobbit: The Battle of the Five Armies trailer. You can check that out below:
What makes this post somewhat convincing is how it syncs up with a lot of the other rumors that we've recently heard regarding Avengers 4 and this first trailer. An extensive leaked trailer description points to a series of footage that picks up with the somber reality of the Marvel Cinematic Universe after "The Snap" in Avengers: Infinity War, before moving into the teases of a multi-faceted sci-fi epic, which sees Ant-Man discovering the time-travel abilities of the Quantum Realm, and using that as a the means to give the Avengers a chance to fix the timeline by stopping The Snap before it even occurs.
Just read the alleged description of the Avengers 4 trailer here, and then imagine that footage set to the tune of "Dust and Light". The images and sounds would certainly sync well, so maybe the post on this Russian site is actually on point. Avengers: Annihilation seems to be the fan-theory frontrunner for Avengers 4 titles right now, and it was recently confirmed that the Avengers 4 trailer will be here before 2018 ends. While December has two big Marvel/Disney releases in Spider-Man: Into the Spider-Verse and Mary Poppins Returns, November 29th would be the one-year anniversary of the Avengers: Infinity War trailer release, which would be a fitting occasion for the Avengers 4 trailer to drop.
Of course, it must be mentioned that we don't actually know any confirmed information about Avengers 4's title or trailer yet, and that any of this speculation must be taken with a huge grain of salt.
Avengers: Infinity War and Ant-Man and the Wasp are now available as a digital download as well as on Blu-ray and DVD. Upcoming Marvel Cinematic Universe movies include Captain Marvel on March 8, 2019, Avengers 4 on May 3, 2019, and Spider-Man: Far From Home on July 5, 2019.