Fans have spotted that Firaxis seem working on something within XCOM 2, and going by Steam Database they've opened a new DLC entry for the game - suggesting a new expansion for XCOM 2 similar to War of the Chosen may be on the way.
There has been a lot of activity around XCOM 2 within Steam, which suggests that Firaxis are preparing something major for the game.
Fans have also noticed that a new DLC entry for XCOM 2 has appeared on Steam, although that hasn't been updated in a couple of months - but then it's not out yet, so it wouldn't be.
UPDATE: Reddit user mazisky has spotted that the DLC entry in Steam Database is nicknamed "TLE", which could be the expansion's title initials. Or, it could just stand for "The Latest Expansion" or some other codename. That hasn't stopped Reddit from suggesting some great names for the DLC, including "Tough Luck, Ex-com", "The Lederhosen Event", and our favourite "Tried. Lost. Everytime." which sounds like our last playthrough of War of the Chosen.
While XCOM: Enemy Unknown only received one expansion, the excellent Enemy Within, most Firaxis games receive at least two expansions a year apart - Civilization V, for example, had Gods & Kings in 2012 and Brave New World in 2013. The last XCOM 2 expansion, War of the Chosen, came out August 2017 and was well received - so it's entirely possible Firaxis could be planning on another expansion in 2018.
XCOM 2: War of the Chosen was announced at E3 2017 - could this June's E3 2018 bring an announcement of another new XCOM DLC expansion, or could it come even sooner than that? More on this when we get it.