Usually “open source” for an LLM means you get the weights and the inference code, which I’ve started calling “open inference”. It’s certainly good and useful, but it’s not the actual source of the model.

I find people get into silly arguments about the terminology because they’re focused on whether the “source” is “open” and not on what the “source” is actually the source of.

“Weights available” indicates even the weights aren’t “open” in the usual software meaning of the term, as they typically come with restrictive licenses (more restrictive than copyleft or attribution).