From the case itself:
Undoubtedly, we are approaching new frontiers in copyright as artists put AI in their toolbox to be used in the generation of new visual and other artistic works. The increased attenuation of human creativity from the actual generation of the final work will prompt challenging questions regarding how much human input is necessary to qualify the user of an AI system as an “author” of a generated work, the scope of the protection obtained over the resultant image, how to assess the originality of AI-generated works where the systems may have been trained on unknown pre-existing works, how copyright might best be used to incentivize creative works involving AI, and more.
So the question of how much human input is needed is still up for debate. I doubt any prompt will pass the creativity mark, but I suspect with a creative enough prompt you will likely be able to claim copyright and author ship over the works.
This case did not explore either of these ideas, only that you cannot claim the AI as the author and thus claim copyright via the work for hire clause in the copyright laws if there is no human input into the process.
This ruling IMO makes sense and is inline with other cases (such as photos being taken by an animal with no human input are not copyrightable). And IMO this is a good ruling - makes it harder for large numbers of images to be copyrighted on mass by companies or companies that own the AI claiming copyright over works their AI generated (even if the prompt was given by others).