Seasonal Events: Holiday-themed maps and limited-time game modes are baked into these update files.
Base XCI files rarely contain updates, though some advanced tools allow users to "superimpose" or merge updates into a single modified XCI file. Why You Need the Pokémon UNITE Update File Pokemon UNITE Switch NSP XCI UPDATE
Newer game updates often require your Nintendo Switch system firmware to be updated to a specific version to run. Safe and Official Alternatives Pokemon UNITE Switch NSP XCI UPDATE