Hi @JoBarbier,
I just tested this in my environment, and students with no submission still appear in SpeedGrader as they have before (grayed out in the student list, but can still be selected and graded).
The only reason I know of that a student wouldn't be listed in SpeedGrader is if the assignment wasn't assigned to them (maybe it was assigned to just section 1 when the student is in section 2, or assigned only to specific students). Could you check the assignment settings and make sure the "assign to" area is set to everyone, or at least a section the student you're trying to grade is in?
Let us know what you find!
-Chris