Ever since Marvel decided to not reveal the title for Avengers 4, theories have run rampant on the internet. From things such as Infinity Gauntlet (which it was called at one point), Forever, Eternity, Heroes Reborn, and any combination of those with “War” added on for variety are all wrong.
For a long time people believed that the title would be a spoiler for Infinity War, because Kevin Feige said so. The origin of that was an interview with Cinemablend:
Me: When I talked with Joe and Anthony Russo last year, I guess a couple months ago, they mentioned… we [the public] don’t know the name of Avengers 4, that they’re not going to announce it, it’s going to be a minute. I’m curious if the reason for that is because it’s a spoiler.
Kevin Feige: Yeah, for sure.
But now that doesn’t appear to be the case.
According to writer DanielRPK, who knows the title and has recently got such things right as Ava DuVernay, Spielberg, and Peter Jackson circling DC projects as well as Affleck staying as Batman; the actual title is not a spoiler for Infinity War. It also is not a title taken from any comic story line, and it doesn’t have “War” in the title.
Apparently we’ll learn the title soon, either officially or unofficially. It sounds like it even could come within the next week or so one way or the other…