If they release a new version, it will have a new tech sheet published. As it is, the tech sheet #E-4040, which has all the older versions of Portra including 800, is listed in the discontinued section. As I said, if they are going to make a new version of the 800, it will be announced when the current stock of it gets to within two months of running out. If it sells too slowly, however, it may just get the axe and they leave us with 160 and 400.
But don't take my statements to mean they will get rid of Portra 800, it just seems this is the model they are following for releasing the other two.