What happens to EU court decided cases after Brexit?Watch
Nothing. Changes to the law cannot be applied retroactively, so any past judgements typically remain standing.
Not true. They will continue to be persuasive precedents. For example, if the EU privacy law is adopted into English law through the Great Repeal Bill, the EU judgments will continue to be persuasive if not tantamount to binding. It's similar to US courts who refer to English contract judgments from the 19th century.
But again at the end of the day judges are unpredictable beings