I was messing with a villager breeder that I had left stagnant for a while because I wanted to gain the "Very Very Frightening" advancement, but after repeatedly striking the witches with my channeling trident, I was granted the "Surge Protector" advancement, despite having never even crafting a lightning rod in this version. My best guess is that the advancement detects when lightning strikes close enough to villagers to signal a lightning rod being used, but not close enough to actually harm them. Unfortunately, my screenshot was taken after the fact, but all that I have stated above is the truth.