The case has been officially docketed.
The fact that the case is docketed doesn't mean the Court has decided to “hear” the case.
While the Supreme Court has original jurisdiction over disputes between states, it is not mandatory jurisdiction, which is why there is a motion for leave to file the case.
Under Rule 17, a motion was filed, so it gets docketed and the court sets a deadline for response.
Thereafter, it decides whether to hear the docketed case.
So, maybe the Court will agree to hear the case, but it has not done so yet.
