Earlier today, Nintendo decided to push back the Nintendo Direct they planned for today. Nintendo said they would share a new date/time soon, but it looks like we might not have to wait for them to announce it.
Splatoon 2 dataminers have been pouring through the game as usual, and they've found some interesting info. The ranked rotation pool with Starfish Mainstage that was supposed to start on September 7th has now been removed. In addition, all current rotations are preset until September 14th. Finally, the Salmon Run gear that was scheduled for September 7th has been pushed to Sept. 14th.
Looks like we could be seeing the Nintendo Direct rescheduled to Sept. 13th, 2018. Not a confirmation by any means, but certainly some solid evidence.