That is something they could do but I do think that the current cards aren't really themed enough for me to think of what to do as alternate versions since if the sets were more era based it'd be easy as with Apink alone you could have like 3 eras one being I Don't Know, another being either No No No, Mr. Chu, LUV or Remember era and one more being I'm So Sick, %% or Dumhdurum era.
You already have some of the current sets like Gfriend with 4 different eras in them and Yerin isn't from a specific era as it's just a photoshoot thing they did so that presents its own difficulties however if there was alternate versions that'd have a cohesive theme then even just putting them in with their original set would give longevity like imagine alternate NCT cards being added to the 1st batch