It's been years since they disappeared, and they've probably gone through quite a bit in that time. Couples don't always stay together. It's possible that during their adventures in the beyond they grew apart, or someone betrayed someone else, and we'll get a hero for each side. The expansion could be the story of their battle, and their reconciliation. All sorts of opportunities for drama.
That would be nicely complex, although I know it would disappoint the people who want a simple romantic story. I like my romances more complex.