NFPA is not part of RVIA. Separate entities. However, RVIA uses the NFPA 1192 standard as their standard for design of RVs. Much like cities use NFPA 70 National Electric Code for their building codes.
The NFPA 1192 standard is a little grey in that area. It states that where an RV has more than one sleeping area and one area uses the door as the primary means of escape then no other means of escape is required for that area. That is a pretty far reach for the manufacturer to claim the forward door is the primary means for escape from a rear sleeping area, but I would guess that is their poor reasoning.
For a MH, 1192 permits the driver's door can be the secondary exit. That means a long MH with sleeping in the rear would be permitted to use the two doors at the front as the primary and secondary means of escape.
Would probably require a law suit and a court legal ruling to get any action from the manufacturer. But it would not hurt to push it as far as you can without getting into court battles.
