Nintendo announced in the Immediate Demo that Xenoblade Chronicles 2 will be getting an Expansion Pass once the game releases for the Nintendo Switch December 1.
As they are released the expansion pass will retail for $29.99 and will give access:
December 2017 – Support Items for Your Journey
January 2018 – New Quests for the Main Game
Spring 2018 – New Rare Blade
Summer 2018 – New Challenge Battle Mode
Fall 2018 – A Brand-New Story and Adventure
Unfortunately, the packs will not be available for purchase individually. It’s best if you buy the Season Pass to get all of the above contents.