Fans have known for quite some time that Avengers 4 will be the final movie of Marvel's Phase 3 slate, which will, in essence, mark the culmination of the MCU as we know it. Marvel Studios president Kevin Feige reiterated this in a new interview, which many fans interpreted to mean that the end of Phase 3 will be the end of the Marvel Cinematic Universe all together. But that isn't the case, according to Guardians of the Galaxy 2 director James Gunn. When asked by a fan on Twitter if the Marvel Cinematic Universe will truly "end after phase 3," James Gunn had this to say, revealing that Avengers 4 will start a whole new story set within the MCU.
"No. Read Kevin Feige's quotes & not the static around them. It's the end of one long story & the beginning of another. And one of the films that will kickstart the new story will be #GotGVol3."
It has also been confirmed that Spider-Man: Homecoming 2 will hit theaters on July 5, 2019, just a few months after Avengers 4 arrives on May 3, 2019, making it the first Marvel Phase 4 movie. It has been confirmed Avengers 4 will bring the 22-movie arc from Marvel Phase 1 through 3 to an end, with Spider-Man: Homecoming 2 addressing the aftermath of Avengers 4, and where the story will go from there. With all of that being said, with nearly two years left until Phase 3 comes to a close, Phase 3 may certainly be the end of the first three phases of the MCU, but it won't be the end of the MCU as a whole.
Aside from Spider-Man: Homecoming 2 in July 2019, it remains to be seen if Marvel plans on fitting a third Marvel movie in for 2019, perhaps in early November, as has become the MCU's new tradition. Way back in October 2015, Marvel even set three new dates aside in 2020, May 1, 2020, July 10, 2020 and November 6, 2020, which fans at the time assumed would be the first Phase 4 movies. One of those movies will likely be Guardians of the Galaxy Vol. 3, with director James Gunn essentially confirming that it will arrive in 2020 during a lengthy and heartfelt Facebook post. While it seems likely that it would follow in the footsteps of Guardians of the Galaxy Vol. 2 and take the May 1, 2020 release date, that hasn't been confirmed yet.
As for what else is coming in Phase 4, that we likely won't know for quite some time. Kevin Feige revealed in a November 2016 interview that the studio has a pretty good idea of where the studio is heading, but any of the Phase 4 movie titles would be considered spoilers for Avengers: Infinity War and Avengers 4. Even the Avengers 4 title is considered a spoiler for Avengers: Infinity War, so we'll have to wait until that movie hits theaters next May to find out more about what the future may have in store for MCU fans. Take a look at what James Gunn had to say below where he clarifies that the MCU is not ending after Phase 3, courtesy of James Gunn Twitter.
1/2 No. Read Kevin Feige’s quotes & not the static around them. It’s the end of one long story & the beginning of another. https://t.co/NA1f0EnQeE— James Gunn (@JamesGunn) October 16, 2017