Even recently, Kevin Feige came out and said that the title for the film would spoil Avengers: Infinity War, hence why the studio has yet to announce what it is.
Now, make sure to take this all with a grain of salt for the time being, since neither Kevin Feige nor anyone at Marvel have confirmed Avengers: Infinity Gauntlet as the film’s title.
But this title does imply something interesting, which is that the two films may be divided entirely around Thanos’ quest to assemble all of the Infinity Stones into the Infinity Gauntlet.
But just because the studio is in the very middle of the intense production schedule for Infinity War, doesn’t mean that Kevin Feige and everyone involved in the film aren’t still being constantly asked about the very mysterious Avengers 4.