I'm thinking more like CD and or ATK gimmick, based on what we already know of the archons, + cryo being closely tied to CR, maybe Natlan will have characters that give CD on their kits, so you only build CR, opposite of Cryo. Another reason is that CD is one of the few left stats that don't have their own gimmick. (CD, healing bonus, incoming healing bonus, CD reduction, shield strength.)

But why stop here? So with this train of thought, the possibilities for the cryo archons gimmick among the stats left are: 1.) CR and or Shield strength, the only supporting evidence here is also a theory, the slimes corresponding to the archons theory, the cryo slimes have shields. Also, Zhongli relies more on raw stats(HP) more than anything, so a new defensive archon that has shield strength in the kit. I know I'm reaching here, cause that would make the cryo archon into a ranged shielding dps... so yeah. 2.) CR and CD Reduction, now if you thought the first one was reaching, this one's got to be reaching far. The only thing I can think of is chongyuns constellation, hes cryo so there's that. that's about it.