Splatoon 2 already launched with a lot of content off the bat (which made for a welcome break from the original game, which was threadbare at launch), but Nintendo had already publicly committed to a cadence of free content for the game to be continued for the foreseeable future.
Now, a datamine for the game, details on which were posted over on Reddit, may have revealed some information of what kinds of new content Nintendo is looking at adding to the game over time. The list comes courtesy of Reddit user OatmealDome, and indicates there are new maps in development, including redone versions of Kelp Dome and Blackbelly Skatepark from the original game, and maps that are tentatively called Line and Tunnel. Apparently, new Salmon Run maps also seem to be in the works, called Shakehouse and Threepoints.
All of this is in addition to a multitude of new weapons that are inbound, including something called the Squeezer. Not much more is known about these, but presumably, Nintendo will be looking at sharing this information officially some time soon. Splatoon 2 is available exclusively on the Nintendo Switch.