User blog comment:PrinceKeShawn/Laurel Lances fate?/@comment-3221148-20160605195828/@comment-3221148-20160605201205

1) And Kit Harrington said that he was leaving Game of Thrones, as his character Jon Snow was "dead for good". Not really. Katie Cassidy may appear later as a guest star easily (Vandal Savage appeared in almost every episode of LOT, and he, too, was technically played by a guest star).

2) Oliver killed Darhk and because he realized that he may still need to kill some truly dangerous enemies even as part of his Green Arrow identity. Laurel's dramatic escape would also play into this reasoning, since with her dead Oliver and Quentin Lance could work together without worrying about repercussions from Darhk.

You know, I don't really care about Laurel, but her death was so strange and suspicious that, after marathoning the rest of the Arrow prior to watching Season 4, I think I can recognize the writers' patterns with their "assumed death -> hints -> shocking twist" scheme.