Debuting on the PC Gaming Show at E3, XCOM 2's expansion, War of the Chosen, is a few months away. The release has been set for August 29th on PC, PS4, and Xbox One.
XCOM is pretty much the gold standard for turn based strategy games for my money and XCOM 2, released only last September, still pulled in a few Game of the Year awards. It's always nice to have solid games continuing to see support and extend their shelf life. War of the Chosen introduces three new resistance factions, each with its own Hero class, to fight alongside the boys of XCOM against the Chosen, a new and more powerful threat. The game also ratchets up the strategery by adding Specters that can summon dark copies of XCOM soldiers, factions and resistance orders, covert strategies, and a challenge mode to test yourself in one-off battles against the leaderboard.
More info about War of the Chosen can be found on the official blog.