Kevin Feige has no plans to stop. The MCU is the biggest powerhouse at the movies aside from Disney's live-action remakes. Although Avengers: Endgame just finished up the decade long Infinity Saga, Marvel is just getting started. There are so many more villains in Marvel comics, and the X-Men and Fantastic Four have not even been revealed yet. Phase 4 will start to build what will be the next Endgame level showdown, and things are already in motion.
According to CinemaBlend, Kevin Feige revealed that the narratives for the next interconnected storyline are already playing out. "Yeah, I mean, the MCU is all interconnected, but we really focus on one movie at a time," stated Feige at Brazil Comic-Con last weekend. "We’re going to make the best Black Widow movie we can possibly make, the best Eternals movie we can make, the best Shang-Chi, Doctor Strange, Thor, Captain Marvel, Black Panther, right? And keep evolving their stories. And then, yes, it's always fun to see them come together in a master plan. Which is, I promise you, well underway." He also hinted at the forthcoming meeting of the Avengers and the Eternals. "The Eternals know about the existence of the Avengers, the Avengers don't know much about the Eternals. Yet," Feige teased.