PM sent. The older the preservation, the less complete the built-in subtitle support would be. Eventually I hope excellent subtitle support just comes standard with any preservation, without having to ask for a separate download--but we're not quite there yet.

EDIT: However, the latest release of Star Wars Despecialized does have English subtitles, so if yours doesn't, you've got an old version and should definitely consider an upgrade--there have been major improvements since the subtitle-free 1.x series.