No, open source means that sources are open, typically for inspection, modification etc. Also here it can be considered the case. Likely in order to claim "true open source", they would have to share dataset? But even this might not be enough for truely open source model? This dataset is nothing but another artifact. So how did they arrive at this dataset, now they have to share pipelines and infra...

.. the thing is, we have not dealt with llm much, it's hard to say what can be considered open source llm just yet, so we use that as metaphore for now