But if there is going to be a fourth phase to the MCU, it is likely that it would feature the other Marvel superheroes or the sequels to the other films.
From the looks of it, it appears that Marvel Studios has allocated up to three movies for each of its superhero. Iron Man had his three, Captain America just had his three. And the next one who shall have his three is Thor.
If Marvel Studios decide to make an “Iron Man 4,” it shall also be obligated to do a “Captain America 4” or a “Thor 4” which seem too far-fetched already. With that being said, the chances of having an “Iron Man 4” hitting theaters in 2020 or later look very slim.
It seems that if there would be a continuation to the MCU, it would already feature the continuation of the other stand-alone films. After the three Marvel superheroes will have their three stand-alone movies, the next one to get his second is Ant-Man, in “Ant-Man and the Wasp.”
Given his popularity among Marvel superheroes, Spider-Man is likely to get his second and also his third servings in the MCU, that is if those two films are within the bounds of the agreement between Marvel Studios and Sony Pictures, who holds the right to the web-slinging superhero.