The idea of having the signature series with seats that were normal seats but simply didn't fold but then having folding seats on the standard production models seems very strange. Even if they had a seat that some people might want for some reason that didn't fold, I see no reason why a large number of signature owners wouldn't be really upset at having a non-folding second row. Is there a single competing SUV/CUV where the second row doesn't fold down? Even if it makes the second row more comfortable, I see that as a niche tradeoff versus cargo hauling (I'd have kids in the back seat in a booster anyway, so I don't think it would make a difference), sort of like the niche executive seat option in the S. What other advantage would there be? If I were a signature reservation holder I'd certainly want to confirm that before finalizing, and if that were really the case the signature reservation would disappear pronto. While all the theories as to what else the second row might do seem sort of far fetched, it seems like there must be something I'm not understanding, because the obvious explanation seems to me to be saying "Guess what, you payed more money for your X, but the normal X's will be a lot more useful."
While I agree with you gregincal about the 2nd row seats, I think being forced to getting the Performance version is a bigger issue, due to the reduced range. Getting a Signature Series vehicle with less range than a cheaper production vehicle is a bit serious IMO, especially to those people who want range over performance.