In this situation, the difference between those two descriptions seems more spiritual than practical.

Not really; a module system that has versions allows you to define dependencies in terms of version ranges, so that if installing a newer version into your app the module can decide in its dependencies if the version is compatible or not. If you are spinning up different names for each module/version then you have to go round updating all your code that depends on the module to use the different name, and you can't select a different one. The point was that Jigsaw doesn't have a concept of version numbers in its module dependency system; they are all dependent upon exact name only.