Rescinding birthright citizenship under Amendment XIV would require the government to definitively establish the citizenship status of all 330+ million people in America.
This is obviously an impossible task, but the techie douchebag billionaires and their subordinate tech worshippers behind the Trump Administration (Musk, Thiel, etc, and their little douchebag hacker boys) want to believe they can do all this by computer, and they don't care about any errors.