If I understand it well, the events of this dj happen after the finale, when the peace is restored because Suzaku killed Lelouch. In the original story Lelouch is most probably dead but could be revived or still here... it's ambiguous. So the author of the dj played on that faint hope. And for the comment why do they cry so much, it's scenes from the past, when tragedy is sure to come, not after cat!Lelouch is back. No need to say everyone else thinks lelouch is dead and only see a simple cat in Lulu. The reason why Suzaku sees him is thanks to their unique bond, like cherry stems. So I think it's a beautiful story, because even if you are sensitive to tragedy, in this one there isn't. It really made me smile. Feel free to correct me if I'm wrong, after all I haven't seen or read the original, but (extensively) read about it on wikia an hour ago to prepare to understand for djs about it.
