That being said, Avengers 4 will maintain close ties with Infinity War, and Josh Brolin is listed as reprising Thanos in Avengers 4.
A big part of this stems from the fact that Avengers 4 has evolved to become its own entity since the original announcement of Phase Three a few years ago.
So even though next year’s Avengers flick could potentially introduce a new villain or see a new challenge come to light, we should expect Thanos to remain an important player in the final chapter of the MCU’s Phase Three.
Early on, it was suggested that Avengers: Infinity War would be split into two features that would play out over the course of a year, but now the movies are no longer being looked at as two halves of the same story.