...as new projects get created by teams working on them and as some projects get archived.
I don't see an easy solution (except for creating Umbrella projects and Herald rules to automatically add them which is a Phab performance issue and likely not wanted by some maintainers) and while some (WMF) teams list their codebase projects they are responsible for in some places (on-wiki or Phab team project descriptions) there is no consistent approach enforced.