I don’t think there’s any strict reason they can’t from their contract. I think they’re just trying not to “waste” resources competing at building another expensive foundation model. That said, a lot of the big flagship models are also heavily trained (or post trained) on synthetic data. Microsoft has done a lot of application-specific fine tuning research.

This model in particular makes sense to be synthetic though. It’s explicitly trained to control a computer, and I doubt there’s a large enough amount of public training data on this use case.

I suspect that Chinese models are largely forced to open source as a trust building step because of general China-phobia in the west. There’s tons of stellar LLMs available from major US companies if you’re just using an API. It’s also a convenient marketing and differentiation opportunity. Some of the companies behind the bigger “agentic” models have started to offer a cheap subscription alternative to US companies. If they build up a big enough business I wouldn’t be surprised if they stop open sourcing right away.