User blog comment:SayuriDarling/The House of Hades Official Discussion/@comment-5360472-20131031124448/@comment-24062146-20131103142504

It is an interesting thought, and with an author like JKR I would think it a strong possibility. However, Rick's time line within this series is kind of all over the place, so I doubt he would have thought to link the two series in this way. Your guess is good, I just don't think the writing is strong enough to support it.