I have seen a huge insurgence of big sleeves/drapes/floats in American Style.
Two of the biggest contributers for American Style are Larinda MCRaven and Maria McGill. Larinda has been wearing floats and large sleeves for quite a while now. It seemes to be very fashionable and lots of top American Style dancers are adapting them now. Maria McGill, as a dress designer, has been adding floats and drapes all over the place. You can spot her designs a mile away, even in the American division.
I am not sure that it really is true about International dresses being less decorated on the front and more so on the back. It seems to be more of an "urban legend", like don't flash your lights at an oncoming car with their light off or you will be shot. Everyone has heard it and you almost half beieve it. But there really is no proof. If you look at any of the dresses that the top girls are wearing, they are beautiful, front and back.
Now if you are an amatuer costumer and trying to save yourself a few bucks, then skimping on the decorations on the front seems to make sense. But this maybe an individule choices, rather than the style as a whole.