^Stores place one order before the season, that sometimes shows up in multiple shipments. There are no re-stocks because there are no re-orders (it would take too long anyway). So what you see is what you get. If you don't snag them this season, your best hope is that they (or something similar) get released again during a future season.
That being said, if you've checked all the US stockists, you can try Japanese stores and keep an eye on second-hand markets.