Docketed means that SCOTUS will consider the petition. It is extremely unusual that SCOTUS does not docket a case; you basically have to be a vexatious litigant to reach that stage.
Considering a petition is not even close to a guarantee of certiorari. There are several thousand petitions filed a year, and SCOTUS will hear about 70-ish cases a year.
The Court does not grant cert for this. Disputes between states are one of the few instances where SCOTUS has original jurisdiction and thus, it is the trial court.
[1] https://www.scotusblog.com/reference/educational-resources/g...