From your own link:
"“To be sure,” the Court further explained, “the requisite level of creativity is extremely low; even a slight amount will suffice."
"The Office agrees that there is an important distinction between using AI as a tool to assist in the creation of works and using AI as a stand-in for human creativity. "
"The Office concludes that, given current generally available technology, prompts alone do not provide sufficient human control to make users of an AI system the authors of the output. "
Where the US ruling differs from others:
"Repeatedly revising prompts does not change this analysis or provide a sufficient basis for claiming copyright in the output."
Where China has had 2 cases where it supported multiple prompt changes + watermark
Also they dont rule out a change:
"There may come a time when prompts can sufficiently control expressive elements in AI-generated outputs to reflect human authorship. If further advances in technology provide users with increased control over those expressive elements, a different conclusion may be called for"
^ I would (and have) suggested that the above would likely cover the masking tools available in most image generators.
Its certainly not a case that "AI generative outputs are not copyrightable".
"There may come a time when prompts can sufficiently control expressive elements in AI-generated outputs to reflect human authorship. If further advances in technology provide users with increased control over those expressive elements, a different conclusion may be called for"
Because any "advancement" in this space is predicated on getting tighter control over the requested outcome.
You can already script a local image generator to come up with random images based on text searches or LLM output. Thats already not copyrightable anywhere.
For example if I code an entire application in c by myself without ai then told ai to redo the whole thing in rust I would retain copyright.
If you just prompt the same application from scratch and accept by in large the outputs. No copyrighht. This is how the vast majority are using it to create new systems not using it as a tool to enhance majority human generated code or images or books etc.
The more it creates from pure prompts the lesser chance you have to claim copyright.