While I haven’t sold my soul to Apple’s gadgets yet (
), I’ve found your analysis quite good.
However I have to suggest a correction… to the title. 
Fine, Llama’s weights are… “weights”.
But how they are “open”?
Maybe you meant “Freeware weights”?
Because you can download and use them for free, but even ignoring the license, they are literally black boxes.
PS:
Actually, the public training data used by Meta are not only subject to copyright law, but also to personal data protection law such as the GDPR.
Yet assuming that you have the right to use such data for training a LLM, but not to redistribute them, nothing prevent you from distributing a dataset with URL, timestamps and sha512sum of each public record you used.
So there is no real constraint, neither legal nor technical, that prevents Meta to grant the right to study and to modify Llama models.
Except, of course, Zuckerberg will. 