First off, thanks a lot to the Wii Sports team. They're the reason why this is happening. I'm simply the messenger posting this information here for y'all.
Some information on upcoming maps:
Incomplete files for revamped versions of Kelp Dome and Blackbelly Skatepark have been introduced in the 1.1.1 update
There are additional maps named Line and Tunnel which are in development
Placeholder images for maps revealed in the Direct named Kawa and Pillar are present. (thanks to the people at TCRF!)
Nintendo is including testing versions of Shifty Station in the updates; however, for Splatfest the game downloads the real stage model and layout file separately. This explains why the existing files include debug and test objects.
The developers are currently testing new Salmon Run stages with internal names of Shakehouse and Threepoints. New files for these maps have been introduced in the 1.1.1 update as well. These are the last of the 4 planned stages for Salmon Run as of version 1.0.0.
How about some upcoming weapons?
Grizzco brand weapons are in the works. A Blaster, Charger, and Brella were found in the files.
A new weapon type called the Squeezer is in development. Here is Sheldon's explanation text for the Squeezer and an alternate version of it.
You can find more about upcoming weapons on the full Splatoon 2 weapons list. (Thank you Lean for providing this service!)
A quick word about Octolings:
What was known as the player's gender from the original Splatoon has now been replaced by a parameter called PlayerType.
Another parameter called PlayerType shares the same values as another parameter, ModelType.
The possible values for these parameters are SquidGirl, SquidBoy, and Oct.
Near those values, we have found an additonal value named OctBoy. This is based solely on information found in the Splatoon 2 executable; we do not have models, text, etc for boy Octolings at the moment.
Additonally, since the values of PlayerType and ModelType are shared, we cannot confirm that the Octolings will be playable either without testing in-game (which isn't possible for any of us to do).
We can't wait for all this content to be released. However, the game seems to be somewhat rushed to completion for version 1.0.0. Nintendo left behind a lot of things even though they tried to clean up the files. Marooner's Bay isn't even finished in this version and its English name is a direct translation of the Japanese text (Don Brako Shipwreck). Nintendo are secretly introducing new files via the balance updates.
Source for the new map data being introduced in the 1.1.1 update:
https://pastebin.com/8AnFQ67E (thanks to SciresM!)
