Starfish Mainstage, which has been closed for reconstruction, is now available in Ranked Battle rotation. This stage will also become available in other modes like Regular and League Battles. We apologize for the inconvenience during this construction work and thank you for your cooperation.
— Squid Research Lab
Source: Splatoon’s Tumblr.
…Wanna play? Buy a Switch.
And if you’ve already got yours, click on Splatoon 2 for everything you need to know about the game. 😀