I hate to say this, but I heard ZERO rattling in the box before I opened the shipping box, the Bandai shipper, or even the retail box. It was snapped off, but laying flat and not moving around. I think static charge might have held it in place.
I only ordered the one (because I can't afford multiples, and barely this one), but I WOULD OPEN ALL I ORDERED, if it was little ol' me. If you resell your extra sealed one some day, you may have to deal with a refund situation if this issue come back to haunt. I know I would always worry about that.