Firaxis just announced a new addition to the XCOM series in the form of XCOM: Chimera Squad. It takes place 5 years after the events of XCOM 2 and focuses on a specific squad of named human and alien characters trying to maintain the peace in a one of the new cities.
It's currently $10 on steam, presumably since it looks like it was built on the XCOM 2 engine. The sale lasts until May 1st, so you'll have time to wait until some reviews are out before you buy it.
I absolutely loved XCOM 2: War of the Chosen, so this is a nice surprise for me. Some of my friend who have played some of the older XCOMs are comparing it at least thematically to XCOM: Apocalypse