While I like the Open Source Initiative's early & principled stake-in-the-ground, as a matter of usage, many things get casually called 'open source' that don't fully fit the OSI 'Open Source Definition'.
And, with regard to the Llama models, it seems to me that all the actual computer-language "source code" to run & train them is available. The specific objection of the grandparent post, with regard to the non-availability of the full training-data document corpus of non-source-code-text, isn't clearly in violation of the OSI's 10-point definition.
There is of course a different problem, a part of the Llama's licensing that does clearly violate the OSI Open Source Definition: its "Additional Commericial Terms" preventing just Meta's biggest competitors from using it – discrimination against persons or groups.
"Rude" is a strangely chosen word here. Rude towards whom? I could maybe accept "misleading", but as a person who don't believe OSI has an ownership of the term "open source", I don't think it's misleading either.
I used the word "rude" carefully here, because I'm not confident that I can make a case for it being illegal or even necessarily misleading (though I personally think it is) - but I'm happy to declare it "rude", partly because rudeness is in the eye of the beholder so I get to determine if I think something is rude or not myself.