While we're all looking forward to Avengers: Infinity War as the next big MCU event, it's impossible to think about that film without wondering what will come after. And, of course, Marvel says what will come after is going to be big. Kevin Feige isn't just the guy in charge of Marvel Studios, he's also the company's biggest cheerleader. He's been hyping up the end of the current MCU phase for quite some time, but now he's promising Avengers 4 is going to be like something we've never seen before, and that it will be a massive finale, with everything after being something totally different. According to Feige...
(Avengers 4 will) bring things you've never seen in superhero films: a finale... There will be two distinct periods. Everything before Avengers 4 and everything after. I know it will not be in ways people are expecting.
It's been previously hinted at that the next phase of the Marvel Cinematic Universe will be something very different than the one we've come to know. The implication is that it will deal with characters and stories that are more cosmic in nature, focusing more on outer space and less on the Earth-based heroes. Calling Avengers 4 a finale in Vanity Fair certainly reinforces that idea. Clearly, the idea is that Avengers 4 will mark a clear end to what has been building since Iron Man came out in 2008.
Having said that, what little we know about what comes after Avengers 4 certainly confirms that not every aspect of what came before will be over. The next film after Avengers 4, following only two months later, will be the sequel to Spider-Man: Homecoming. Unless Peter Parker is replaced by Miles Morales following the reality warping abilities of the Infinity Gauntlet (and, to be fair, that's not impossible), then we know that some characters will not only survive the events of the finale, but continue forward.
Still, the fact that we have some expectation fo what Phase 4 will look like, makes it very interesting when Kevin Feige says it won't be what we're expecting. He does call the post-Avengers 4 movies distinct from what came after. While that could refer to characters and stories, it's possible that it could mean something much more broadly. Perhaps the movies themselves will be changing in some fundamental way. Maybe they'll all take place in an alternate timeline from the one we've been watching so far. Maybe, they'll become much more character focused with less action. Since we are talking about comic book movies the possibilities are just short of limitless.
Whatever is happening, it seems that Kevin Feige thinks it's going to be big. While part of his job is to hype up his product, so far the MCU has done a good job and preventing disappointment. We'll see just how big the finale really is in 2019.