Hari while that would be a nice to have feature, it is not essential to this extension, as the name implies it is primarily for forums that wish to restrict access to members only to have a nice login/registration page instead of an empty discussion list, indexing wouldn't work with or without the extension in that case, so it's not a problem as far as the extension is concerned as it isn't undoing anything, especially since you can choose to leave the content accessible by guests.
The feature you describe is a much more specific use case, it would be quite neat though.
