The idea of global refactoring is mostly that you can decide to modify a private API, and in the process actually update all the consumers of that API, because they all live in the same repo as the component they're consuming. (This is also the argument of the BSD "base system" philosophy, vs. the Linux "distro" philosophy: with a base-system, you can do a kernel update that requires changes to system utilities, and update the relevant system utilities in the very same commit.)