Splatoon 2 update 4.8.0 will be released today for the Nintendo Switch. There is no new content planned for the game with this update as it mostly contains bug fixes.
Splatoon 2 update will be available to download today at 18:00 PST. This update includes various bug fixes and game balance adjustments. There will be no additional new content added to the game.
As for the patch notes for Splatoon 2 update 4.8.0, there are none available right now. They will be updated on the official Nintendo Support website once they update is live on the servers.
The game is available now exclusively for the Nintendo Switch. It is the successor to the first Splatoon game that launched for the Nintendo Wii U.