Note that if you ask on slack, you often will get answers from the core team members. They're pretty open. The main place where plans aren't the most clear is when there are features that everyone knows would be good, but aren't on the top of any of the the main people's to-do list. The JuliaLang repo has over 1000 people who have contributed, so a lot of the time, a new feature is just the result of a community member making a random PR. Stack trace improvements for example, started as a package, got ported to Base, and got improved by a bunch of people contributing to design decisions.