The U.S. Copyright Office has already declared that if it's generated by a machine, without any creative input or intervention from a human author, then the work is NOT eligible for copyright at all.
They believe that "The copyright law only protects “the fruits of intellectual labor” that “are founded in the creative powers of the mind.” Trade-Mark Cases, 100 U.S. 82, 94 (1879). Because copyright law is limited to “original intellectual conceptions of the author,” the Office will refuse to register a claim if it determines that a human being did not create the work. Burrow-Giles Lithographic Co. v. Sarony, 111 U.S. 53, 58 (1884). ... the Copyright Act protects “original works of authorship.” 17 U.S.C. § 102(a) (emphasis added). To qualify as a work of “authorship” a work must be created by a human being. See Burrow-Giles Lithographic Co., 111 U.S. at 58. Works that do not satisfy this requirement are not copyrightable. The Office will not register works produced by nature, animals, or plants.... Similarly, the Office will not register works produced by a machine or mere mechanical process that operates randomly or automatically without any creative input or intervention from a human author."
I'm quoting chapter 300 here: <https://www.copyright.gov/comp3/chap300/ch300-copyrightable-... of the Compendium of U.S. Copyright Office Practices here <https://www.copyright.gov/comp3/>. The compendium is the "governing administrative manual for registrations and recordations issued by the U.S. Copyright Office." In short, for the US, this is an extremely authoritative source.
A future US court ruling or law change could change this, of course, but I sure wouldn't bet on it. The US Copyright Office has lawyers who specialize in this area, have clearly stated their position, and they are citing specific laws and court cases to justify their position. Also, in most cases you can't go forward with a copyright claim without registration (though you can register after-the-fact); if the US Copyright Office won't allow registration, you'll have a really challenging time even starting a court case.
I'm sure there are edge cases and complications. But the essence is only "unsettled" if you don't look for the existing rulings. A Google search will find actual answers from credible, authoritative sources. Sure, courts and Congress could change it, but it'd require a significant change.
While this information is specific to the U.S., copyright is similar enough in other jurisdictions that there's a decent chance that other jurisdictions would come to the same conclusion. European law in particular has a number of similarities in this area; I'd love to hear from those with more background in other jurisdictions.
Disclaimers: I am not a lawyer, and this is not legal advice.