I believe they will be adding more items to the calamity salvager to solve the problem. That way, once you unlock an exclusive (one-time) reward but don't have the room to store it, you can just throw it away and buy it again and again when you need it. This allows us to continue to utilize things we've won and solves the data limit on the Armoire (which instead will be used for items you need access too frequently to save yourself from buying them over and over).