In the latest preview (1.20.20.20 preview), a really old bug was patched. It was a texture bug from 1.12 (Village and Pillage Update) which totally changed the texture of villagers but leaved, on bedrock, the zombies villagers with only one unique texture for every professions and biomes, contrarly to java edition. It was a significant bug and it was patched years ago in this preview. Indeed, it corrected the professions issue, so that every zombie villager wear corrects clothes for his profession but the biome issue was not corrected and now, zombies villagers wear specific clothes for jobs but display the same gray tunique w/o biome customizations. However, another bug is that baby zombies villagers display biomes customizations correctly