I wondered that as well, if there was any left. Historically, for non D23 shows, I have seen the leftover merchandise be released in the parks, like the Sci-Fi event at DLR, and Trade City at WDW (certain shops only). The rules were still in effect as far as I could tell, like if it was a DVC exclusive pin, or an Annual Passholder Pin, you had to present the proper ID to show you were a member, so if they do that for the D23 merchandise, I wonder if you will have to show your D23 ID (is there such a thing)