It also means you can take that Super Mario Odyssey game save with you if you end up buying the new Switch models Nintendo is rumored to be releasing later this year. That's if you think a beefed-up Switch is worth the upgrade, or if you want the cheaper, more portable model (maybe for the kids?). Bear in mind, however, that transferring a game save to a new Switch will wipe it from the source system.
The update, version 8.0.0, also packs 15 new user icons (from Splatoon 2 and Yoshi's Crafted World), the ability to set your region to Hong Kong, Taiwan or South Korea, more ways to sort software (by time last played, total play time, software title, and software publisher), a zoom feature, and restrictions for VR Mode within parental controls. Switch owners should get the update automatically, but you can manually start it via the system settings if not.