For clarity, llama etc are not open source because of the conditions on the license under which the weights are released. It may not be possible to copyright weights or to apply software licenses to them, it hasn't been decided by the courts. But everyone acts like it's possible, as evidenced by the licenses they use. So under that assumption, Meta is not using an open source license with the weights.
Edit: for greater clarity, the open source definition has the following clause
The license must not restrict anyone from making use of the program in a specific field of endeavor. For example, it may not restrict the program from being used in a business, or from being used for genetic research.
Similar things appear in the debian free software guidelines, fsf free software definition, etc.The Meta Llama license lists restrictions on field of endeavour. Ergo, not open source. There are other clauses (the one about the number of users) which would also disqualify it, but the use restrictions are the most egregious.