Basically, completely open source with a non-commercial license. I'm not sure why so many people keep saying it 'leaked'. It's just using open source weights not directly from the provider in a way that violates the software license.
There is no reason to believe they are, which means any restriction placed on the weights themselves is bullshit.
It does, if you choose to keep them internally as a trade secret.
It does, if you share it only with people you contract with not to disclose it.
But, for copyright specifically, rather than “some legal protection” more generally, the “it takes millions of dollars” argument is a financial recasting of the “sweat of the brow” concept which has been definitively rejected by the courts.
Why would they be? I mean, what is the specific argument that they fall within the scope of the definition of what is copyrightable under US law?
'copyright' seems to refer to a specific string of symbols. literary or musical styles can't be copyrighted, but individual sequences of letters or notes can. Basically, if a derivative work copypasted without adding anything, it's considered plagiarism and/or violation of copyright.
Weights in a model would similarly be a long string of symbols that someone went to considerable trouble to collate and therefore fall under copyright.
The point here is that copyright requires a human to have created something using their own labor/creativity.
The result of an algorithm run by a machine isn't a creative work under these definitions.
From the US Copyright Office[1]: "A mere listing of ingredients is not protected under copyright law", and from their linked circular on that page [2]: "forms typically contain empty fields or lined spaces as well as words or short phrases that identify the content that should be recorded in each field or space".
A list of identifiers and their weights seems pretty explicitly not protected under one or the other of these.
[1] https://www.copyrightlaws.com/copyright-protection-recipes/ [2] https://www.copyright.gov/circs/circ33.pdf