There has been a lot of hype around Infinity War, The Avengers and the overall MCU. One thing that is certain is that Avengers: Infinity War has lived up to the hype brought forth by the marketing and the fans. One of the aspects of the hype is the title of the upcoming Avengers 4 which was original referred to as Infinity War Part 2. They changed the title into something that they have not released to the public yet. One of the reasons behind this is that the title would be a spoiler to Infinity War. Now that a good number of people have seen the movie, there are more educated theories on what the title of Avengers 4 could be.
One title that people are thinking it can be is Infinity Gauntlet. Even though this title is denied, it does make sense because the Infinity Gauntlet comic book series involves a version of the events that happened in Infinity War (although it has played out differently in a lot of ways).
Another title that people are bouncing around is The Secret Wars. This involves time travel and many people think that a lot of what has happened at the end of Infinity War is going to be reversed with the time stone.
The Russo brothers have stated that the title of the film will deal with the heart of the story. Therefore, some people are suggesting that the title might be Avengers: Endgame for many reasons. One reason is that this comes from a line spoken by Doctor Strange where he said that they were in the endgame. This is also partially because the people responsible for the MCU have suggested that this next Avengers movie is supposed to be the end of the MCU as everyone knows it. Another title that has a similar effect is Avengers: Rebirth, which plays with the idea of bringing the MCU into a new era with new characters.
The Russo brothers have reportedly stated that Avengers: Infinity War was a greater challenge than Avengers 4. While some may take this to mean that Avengers 4 will probably not be as big as Infinity War, this could also mean that there have been plenty of challenges that they had to overcome in Infinity War. Then by the time they got to Avengers 4, they have gotten used to the challenges. At the same time, it is very likely that they are going to be dealing with fewer characters than Infinity War depending on what happens in the upcoming film.
One thing that has been reported on is the apparent plot elements of the post Infinity War film. For one thing, it is said to involve time travel. There have been looks of Robert Downey Jr and Chris Evans in their previous MCU looks which indicates earlier eras of the MCU. For one thing, many fans have speculated on what is very likely to happen in the upcoming Avengers film. One thing that is certain is that it is loosely based on the Infinity Gauntlet as well as some of the other stories that feature Thanos.
Given that the Russo brothers have made it clear that the fact that they are holding out on the title should scare fans, it is very likely that there are going to be a lot of scary and heartbreaking events in Infinity War. These events are also very shocking to the point that the Russo Brothers have made sure that the real script did not get out into the hands of anyone other than a few people. Given that some actors have an issue with revealing the secret plot lines, the directors have taken it upon themselves to make sure that even the actors are unaware of what could happen. One thing that they have done was give out scripts with fake scenes so that people will not know what is actually going to happen.