if it's not stated on the box probably not.
But then again I wouldn't worry about it cause without windows 8.1 you wont get it anyway and you'd have to hate yourself to use it lol
Will the 700 series or 780GTX be able to support DX11.2?
They'll be 'compatible' but they wont be true DX11.2, to get 100% of the DX11.2 benefits you'll have to wait until October for the first true DX11.2 GPU's from Radeon, the 9000 series.