They did release more, but it was in very limited quantities. (Only NISA really knows how many were actually put out.) I've been watching this situation very closely, they sold out within a few days of being restocked, and unfortunately I've seen more than a handful show up on eBay at twice the price just to be resold for a profit. Shame on those people who bought it just to do that. Some people selling it weren't even offering the replacement discs with it that came with their NISA purchase, but were more than happy to include the poster. How sad. I just wish there was a way for me to call them out on it, but that's not something eBay would want to promote.
After this run though, I highly doubt NISA will put more of them out there, even though they're probably still likely to sell, and they still have plenty of Vol. 2 Premium editions to push. It's unfortunate, but I'd say it's worth a shot to send them a mail if you'd like to see them release more. Otherwise second-hand sellers might be one of your only other options.