I'm intensely curious to see what they do as the next big "event" that would warrant another 10-year buildup, if they even decide to go that route again. Because as far as cosmic-level events go, you can't really do higher stakes than Infinity Gauntlet. Only one I can think of is Secret Wars 2015; all the other big events are limited in terms of scope where it wouldn't affect every single character. Even someone as big as Galactus is only a planet at a time. They could just end up making their own story, or maybe they're thinking about an MCU Multiverse where we're getting stories/characters from alternate realities