Will retired Prestige skins like Kai'Sa make a return?

Hey everyone,

As the title suggests I'm curious as to whether Prestige Kai'sa or other retired Prestige skins will be joining us in the Prestige Shop. I didn't have a chance to buy the Kai'Sa skin during its event but I would be willing to buy it with Prestige points, assuming I get the chance, which hasn't exactly been made clear to me.

Personally i don't see any reason as to why the old Prestige skins would unpurchaseable when the rest of the skins seem to be sticking with us for the forseeable future and maybe I've missed a thread/announcement, but I would just like to know if I'm going to have to try my luck with rerolls or if I actually have a realistic chance to obtain the skin.