Just About Anything Would Have Been Better
If they were open to pulling from the comics, how about just "Infinity Crusade"? It follows up on Infinity War and could hammer home the idea of Captain America and the surviving heroes going on something of a crusade to save those that were lost, or at least avenge them.
Then again, "crusade" probably brings up some awkward connotations for a superhero movie, and perhaps the tone of this film doesn't quite match what that word suggests. After all, the survivors in a universe that lost half of all life in an instant is probably aren't getting ready to go on a crusade.
Using Avengers: Disassembled would have worked well, considering half the team is now dead, and everyone else is disheartened. It would definitely set up ideas regarding whether the Avengers ever accomplish anything, or if they ultimately fail.
However, the perfect movie to use Disassembled already came out: Avengers: Age of Ultron. We don't yet know what will happen in the fourth Avengers movie, so it's possible disassembling the team is never actually part of the narrative, and is instead more about soldiering on.
That then leaves us with perhaps the best possible title not used: Annihilation. It brings up the same thoughts as Endgame, but with more of a sense of sudden destruction, after what happened in Infinity War.
Where We Stand with Endgame
Marvel and Disney obviously held back the title as a marketing ploy. In the wake of Infinity War, the release of the first trailer was supposed to start the conversation all over again: The Avengers are back. Unfortunately, the title doesn't really say much, other than indicate where we are in the superhero cycle. In case you were wondering, we're at The Last Stand Before the Inevitable Rebirth part of the cycle.
In the end, Avengers: Endgame very much feels like a sequel title. Maybe it's not as bad as Speed 2: Cruise Control, but it's proportionally close. No one wants to think that, but it might have been better just to call the film Avengers 4 and be done with it. Everyone was calling the movie that anyway, it feels more like a standalone film, and its more clean and precise than Endgame.
Make no mistake, this movie is still going to be a box-office juggernaut and a crowd-pleaser, so the title is a triviality. Still, the filmmakers blew it. Playing this guessing game really backfired, because in the end, would anything have lived up to the anticipation?
Avengers: Endgame will release on April 26, 2019. Directed by Joe and Anthony Russo, Marvel’s Avengers 4 stars Robert Downey Jr., Josh Brolin, Mark Ruffalo, Tom Hiddleston, Chris Evans, Chris Hemsworth, Jeremy Renner, Chris Pratt, Elizabeth Olsen, Sebastian Stan, Benedict Cumberbatch, Paul Bettany, Samuel L. Jackson, Cobie Smulders, Benedict Wong, Zoe Saldana, Karen Gillan, Vin Diesel, Dave Bautista, Pom Klementieff, Scarlett Johansson, Tom Holland and Anthony Mackie.