Maybe I'm wrong, but in looking more at these, I suspect they're actually Low Straights that have been mislabeled. They've done this before, only to correct it later. All the new seasonal styles adhere to their existing fits (straight, low straight, slim, slim bootcut) and I can't imagine them coming up with a completely different cut but keeping the details the same (in this case as the low straights). Like I said, maybe I'm wrong but wouldn't be surprised to see them change the description soon.
As for the 16 oz American denim, I'm very curious to see what that feels like.