An expansion for XCOM 2 has been announced to be released end of August 2017. I’m looking forward to that since XCOM is one of my favourite games.
Personnaly I liked the scenario of XCOM much better than that of XCOM 2. XCOM 2 is too dark with the player taking the role of an underground organization on alien occupied Earth. I rather played the international defense forces protecting the planet against that invasion. I also missed the air combat in XCOM 2 (I know a lot of people didn’t like that part of the first game).
Anyhow gameplay-wise XCOM 2 is better than it’s predecessor, so the expansion will hopefully be great…