Content Update 12/21/2017

I think this might be another money-grab tactic. You might think people would not buy crystals if they are not on sale. But they might be banking on players buying crystals for full price to prepare for CLS. So they designed the pop-up sale idea to make discounted crystals difficult to buy. This forces a lot of players to buy crystals at full price to ensure they will get CLS, while also saving-face with players by having some sort of sale on crystals like they always have in the past. I wouldn't be surprised if this has something to do with Jedi Rey being not-so-popular. They didn't make enough money off her, so they have to make it up in some way...