There is no mention of Katie in these press release’s but as Cayden James is in both I would say Katie will be there as well.
WILLIAM LANDS IN CAYDEN JAMES’ CROSSHAIRS — Cayden James (guest star Michael Emerson) ups the ante by launching his plan to take control of every aspect of the city. Despite the scope of Cayden’s plan, Oliver (Stephen Amell) is determined to foil it with just the Original Team Arrow – and without the aid of Rene (Rick Gonzalez), Dinah (Juliana Harkavy), or Curtis (Echo Kellum). But things get complicated when William (guest star Jack Moore) is endangered as a result of Cayden’s handiwork.
OLIVER AND DINAH FACE OFF — Oliver (Stephen Amell) continues his battle with Cayden James (guest star Michael Emerson). Dinah (Juliana Harkavy) and Oliver have a major disagreement that endangers the life of one of their own.