The Washington media abhors a vacuum.
And Rod Rosenstein was supposed to vacuum himself out of his job by mid-March. That date has come and gone, and so today Pete Williams chuckled that whether it's breaking news or folding news, Rod Rosenstein is not leaving his job at the Department of Justice and will stay for an "indefinite" period.
My not-so-wild guess is that Barr wants a pistol in that position, to shield his own office once the Mueller report is released to the public. Best the report gets released by Rosenstein who then makes a quick and unsurprising exit from the department.