It is procedural, and it's not the shadow docket, per se.
They have, or at least six of them, decided to let it run its normal course. I suspect even the liberal judges (assuming they actively want to fuck Trump), have some qualms about not letting it run through the DC Circuit first. It is conceivable that they quickly deny cert if they're content with the DC Circuit's analysis. Some have predicted that will happen in the Blassingame civil immunity case.
But here's the problem: Trump cannot be tried with an immunity question pending on appeal. Nor can he be subjected to discovery, but then criminal defendants aren't really subject to discovery. In any event, if the appeal remains pending on March 4, or near it, the trial date will move.
I am reasonably certain that the DC Circuit will resolve the case in late January or February, before March 4. Petitioning for cert does not automatically stay the return of jurisdiction to the trial court, thus freeing the case for trial. But the DC Circuit could rule that it should in this case.
Even if they had granted cert and expedited the briefing and oral argument, I'm not sure the Supremes, any of them at any point in history, would resolve it before March 4.
The trial date will move, it's virtually guaranteed. The question is, how far.
It's a freak show, baby baby on the dance floor. Freak. Show.