I personally would not be too surprised if a lot of the stuff that is supposedly going to be banned is still for sale after August 13. It may be that ebay wants an "official policy" that gun related paraphenalia is forbidden, and then turn a blind eye to their own policy. This may, in the eyes of their lawyers, lessen their liability if someone uses a product sold on ebay in a crime.
They certainly would not be the first company to have an official policy to simply limit their liability. Colt still stamps AR's with bayo lugs and flash hiders as Law Enforcement Only, and Ruger does the same thing with 20 round M14 mags.