Or they could just go with achievements. Clear X levels in cata with Y weapon and get a skin for that weapon. Bam, you have to do multiple cata runs, the condition is contingent on actually using the weapon so it encourages using a variety of weapons, and it doesn’t have RNG tied to it.
We have no idea how Lohners shop is gonna work, have to wait and see. The Devs have said before that Cata is not for getting loot, Legend is the end game, Cata is just for people who want a challenge. So locking loot behind it is probably not something they’re interested in doing.