The standard form for dealing with orphaned playlists is to attach them to the Root

The playlist "fixing" code in emplode, when shown a Central, will do basically what Mike describes: playlists that aren't directly attached to the root (whether orphaned or not) are reattached to the root. This isn't the same as flattening them.

Tunes that aren't attached to any playlists are left alone -- they don't have to be attached on Central.

Tunes that are in the root playlist are detached and left orphaned.

Basically, the invariant is that you can only have playlists at the root, and that they can only contain tunes.

If you ask nicely, Peter might be able to make the next alpha release of emplode not do this to Centrals -- it's just a flag in one of the header files in lib/model.