Marvel's Kevin Feige has revealed that he considers Spider-Man: Far From Home to be the end of Phase 3. Although the wall-crawler was one of Thanos' many victims in Avengers: Infinity War, it's long been an open secret that he'll be coming back. As far back as June 2017, Marvel figures were confirming that the next Spider-Man film would be set minutes after Avengers: Endgame.
Spider-Man: Far From Home had generally been viewed as the first film of Phase 4, launching the future of the MCU. Indeed, Kevin Feige himself had seemed to suggest that was the case, telling viewers he wanted the highly-relatable Peter Parker to be the one to hold their hands and guide them into what he called the next incarnation of the MCU.
However, it looks as though plans have changed a little. Speaking with a reporter at a fan event in Shanghai, Kevin Feige was asked about Spider-Man: Far From Home. As always, Feige is secretive in his response, but the little he did say will make fans sit up and take note. "It's the end of the third phase," he observed. "You're the first one I've told that to."
This makes perfect sense in terms of the overall narrative of the MCU. Avengers: Endgame is the climax of the MCU to date, an event movie that's frankly unparalleled in the history of cinema. While Thanos is sure to be defeated, there will be massive consequences for Marvel's entire shared universe, and Spider-Man: Far From Home is set to explore these. Feige's comments essentially turn the next Spider-Man movie into an extended epilogue for Avengers: Endgame.
Fans generally assume that each MCU phase will end with an Avengers film, but that's not necessarily the case. It's true that Phase 1 ended with The Avengers, but that was largely because Marvel was taking a gamble with the whole shared universe model at that time; had The Avengers failed, the whole idea would have fallen apart. With Phase 1 a success, Marvel actually ended Phase 2 with Ant-Man. At least Spider-Man: Far From Home will make a more logical conclusion to one of the phases.
Curiously, this announcement does mean the future of the MCU is a whole lot more unclear than we had previously been thought. Feige is keeping his post-Phase 3 plans under wraps; Marvel is known to be pushing ahead with both Black Widow and The Eternals, but neither of those projects have been officially announced. Spider-Man: Far From Home, however, had been considered the only confirmed movie in Phase 4, but now it turns out that isn't the case after all.