as far as i can tell (in game) there's no chance for RS villages to spawn abandoned. is there a chance abandoned versions will be added in the future or if already present, is there a way to change the spawn rates of them? 🐢

They have a 1/51 chance of a village being abandoned just like vanilla. Controlled by the town center start pool weight values. Overriding these files by datapack (see config datapack example for RS) will let you change the weight values here to make the zombie start piece more likely to be chosen https://github.com/TelepathicGrunt/RepurposedStructures/blob/1.21-Arch/common/src/main/resources/data/repurposed_structures/worldgen/template_pool/villages/birch/town_centers.json

lol the wiki says 2% but vanilla is 1/51 chance or 1.96%. Technically incorrect wiki!
https://github.com/misode/mcmeta/blob/data-json/data/minecraft/worldgen/template_pool/village/plains/town_centers.json

whoops! cool, thanks for the clarification 🐢
now i know why the "80 % abandoned villages" mod only works with vanilla villages if its spawn chance is set for every structure individually instead of a "global chance" to generate an abandoned village.