The bottom line is that Sara is reported by a family member as last seen leaving her home at approximately 6:30 am, in a van, wearing a Walmart vest.
Her last phone ping was in the opposite direction she should have been traveling but we do not know what time (I was assuming it was that morning), and the van was later found in an odd location opposite the phone ping direction, yet also not in the direction she would have been traveling. The van was wiped clean, therefore leading us to believe that a professional knew how to hide evidence if a crime.
No one said electronics were off over night, nor does it say they were wiped. They just didn't hold any clues to finding Sara, or a motive to her disappearance.
Knowing the time of the last phone ping is relevant to determine the ruse, but I don't know if it can necessariy help us find Sara. But maybe and here's why. Sara's phone is most likely with Sara. If the perp who disappeared her made a small mistake, knowing that ping time could be quite relevant to knowing what time she was disappeared and the direction she was placed.