Did not know that. The MCU seems like they had some sort of roadmap at the very least. Nobody has ever pulled off a decade’s worth of interconnected films before.
Roadmap is a good way to describe it. There’s a schedule for which movie comes when, but for the most part the filmmakers are allowed to do as they please with their films. Feige, like Kennedy, understands that that’s what makes the best movies (of course sometimes there’s clashes but that’s a different conversation).