Avengers: Heroes Reborn
1996's Heroes Reborn saw several Marvel heroes, ranging from the Avengers to the Fantastic Four, return from the dead. They were thought to have been killed in the "Onslaught Saga," but as it turns out, Franklin Richards had secretly hidden them all in a pocket dimension, before bringing them back to the mainstream Marvel U.
Again, the MCU is obviously telling a vastly different story, but we can all agree that the concept of its heroes being reborn is one that will inevitably happen. The likes of Black Panther and Spider-Man already have sequels lined up, so we know they'll be returning, plus actors like Elizabeth Olsen (Scarlet Witch) and Sebastian Stan (Bucky Barnes) are contracted for movies in Phase Four, so it's not a matter of if, but how they'll be resurrected.
One theory has the "dead" heroes being stored in the Soul World within the Soul Stone. If this proves the be true, Heroes Reborn would be a perfect title, focusing on the mission to return the MCU's fallen to the land of the living (even if it ends up being due to the Time Stone). This title also holds credence because if it had been revealed beforehand, it definitely would have indicated that Thanos killed off a lot of people.
Avengers: The Thanos Imperative
This 2010 cosmic event focused on the Guardians of the Galaxy and Nova trying to close the space rift known as the Fault, in order to stop the another universe (dubbed the Cancerverse) from seeping over into reality. However, the heroes also had to protect (believe it or not) Thanos from the Cancerverse's ruler, an evil version of Mar-Vell, who needed to kill the Mad Titan to allow his dark dimension to thrive.
Once more, it's a totally different narrative from the MCU's, but shares the common denominator of Thanos' philosophy of balancing life in the galaxy. In the comics, he viewed the spreading of the Cancerverse as cosmic balance, which is why he willingly offered himself to Mar-Vell as a sacrifice. On the big-screen, though, the only way he felt he could have achieved this balance was by using the Gauntlet to implement galactic genocide.
With that in mind, Avengers: The Thanos Imperative would work two ways as a title. Firstly, it could be about Thanos' new imperative of preserving the integrity of this universe he's just reshaped and 'perfected,' while for the heroes, their imperative would be to find the Mad Titan and undo the state of disarray he left behind. This title also holds weight because if revealed earlier, it too would have spoiled Thanos' ultimate victory.
Avengers: No Surrender
This recently-wrapped comic event was just as high-stakes as Infinity War. With Earth basically snatched out of reality and key heroes such as Cap, Black Panther and Spidey, to name a few, taken off the chessboard, the Grandmaster and his brother, Challenger, pitted the remaining (and yes, weakened) Avengers team in a series of battles against the Lethal Legion and a resurrected Black Order.
While it too is a far cry from the MCU's Infinity War narrative, the sequel adopting this name could hint at the heroes who survived Thanos' culling dusting themselves off and coming back for another round. After all, the No Surrender title would directly tie into the mentality needed moving forward against the Mad Titan.
Revealing this title early on would also have alluded to the MCU's heroes losing their fight, but as it stands, it's the perfect title to rebound with because it feels like a rallying cry and call-to-arms. More so, it's definitely the philosophy that's driven these heroes over the last decade on the big screen, and one they'll need to harness yet again to save the day from Thanos' godlike grip.
Directed by Joe and Anthony Russo, Avengers: Infinity War stars Robert Downey Jr., Chris Evans, Chris Hemsworth, Mark Ruffalo, Jeremy Renner, Scarlett Johansson, Paul Bettany, Anthony Mackie, Paul Rudd, Elizabeth Olsen, Tom Holland, Benedict Cumberbatch, Chadwick Boseman, Chris Pratt, Zoe Saldana, Dave Bautista, Bradley Cooper, Vin Diesel, Tom Hiddleston and Josh Brolin.