It’s been established in the DC circuit, where basically any challenges to copyright office decisions would need to be brought. For all intents and purposes, until the Supreme Court or Congress decide to weigh in, it’s pretty well established that AI generated content cannot receive copyright. There will probably be some decisions around the edges regarding when human editorial input might result in a copyright being awarded to the editor, but it would be very surprising to see the precedent overturned completely, particularly given its grounding in previous caselaw.