AI Images are NOT protected by copyright. Therefore, they are free to use, share and download. They fall under free use. Therefore, it is also impossible to DMCA or strike someone reposting someone elses AI art. 
If you want to rebel against AI Art, then just repost AI art yourself. You CANNOT be legally charged for doing so. 
If you want to take measures against AI art, use this loophole, and repost it yourself. At some point, imageboards will have to address the issue of the flood of AI art and duplicates. There is no "owner" behind AI art, so it doesn't matter who posted first.