If you run prune with --no-archive, prune still shows you the list of files that it thinks it will archive. It should either preface this more clearly, or simply surpress this list entirely.
This was probably just a bad description -- what prune is showing you is the list of files categorized a certain way. What you've chosen to do with those files is still TBD at that state.
If you run prune with --no-archive, prune still shows you the list of files that it thinks it will archive. It should either preface this more clearly, or simply surpress this list entirely.