Let’s not compare a vacuum cleaner to a complex AVR.
There is huge difference between a rip-in-the-packing-box AVR and a REFURBISHED AVR.
Just a tear in the box = OPEN BOX, not refurbished.
There is no “could be” or question about it.
Open Box = store returns or display model, full new factory warranty.
Refurbished = AVR was sent back to the repair center, then sent to store, you do not get full new factory warranty.