The law says that jailbreaking is legal, but it doesn’t say that Apple can’t stop you from doing it. Apple’s jail is also legal, and you can only break out of it when Apple makes a mistake. I wouldn’t defend antitrust as a “consistent legal theory,” but if Epic wins this case, all iOS users would have the freedom to use alternative app stores, not only those who manage to find and exploit vulnerabilities before Apple patches them.
But the DMCA also prevents you from reverse engineering Apple's software, so although jailbreaking is legal, you are not allowed to work on a new jailbreak.
