Again there is no mention of Katie in the press release but I would say she will be about,
CAYDEN JAMES LAUNCHES A FULL OUT ATTACK — Cayden James (guest star Michael Emerson) discovers a secret about the Green Arrow (Stephen Amell) that pushes him over the edge. Knowing everyone and everything he loves is in danger, Oliver must decide if he can do this alone or if he needs to turn to his old teammates for help. William (guest star Jack Moore) starts to demand more of Oliver’s time
Arrow 6×14 – 6×16 – Titles
6×14 – Collision Course
6×15 – Doppelgänger – Could this one be about Laurel?
6×16 – The Thanatos Guild