Videos appear to show two different vehicles when it comes to the underfloor rear storage area. My guess is that they filmed one R1S with spare while being introduced to the vehicle by Rivian personal and were given a second R1S without spare for the actual trip.
Screen grabs with one of the...
Video of particular interest is admixed with other stuff (including front end PPF on an El Cap R1T) but some nice footage of black R1T pre and post stealth wrap.