It’s bureaucracy. The hearing is well before the scheduled execution, and it sounds likely that the hearing will vacate the conviction, from what I read. The court is just saying that there’s an established process for this and the lawyers just need to follow that process.
ETA: Not to say that our legal system isn’t horribly broken, because it is. Just saying that my interpretation of this case is that Marcellus is just a few dotted i’s and crossed t’s away from being a free man.