This doesn't pass the sniff test.
Consider that the US was intimately involved with the start of the FOSS movement. Compilers and commercial operating systems are hugely valuable.
Also consider that history the world over is littered with counterexamples. Historical China itself is rife with examples of technological secrecy and exclusivity.
No competent government will voluntarily release (or allow to be released by its subjects) technology that would give them a meaningful advantage on the world stage.
The recent Stratechery piece talks about some of this, most relatably "commercialise your competitors" [0].
By releasing their models, they effectively sabotage the entire US AI industry, and given that that is underpinning a sizeable % of US GDP at the moment, therefore sabotage the US economy.
That may not be their intention. The USA is also their biggest customer, after all. But it does show that there are other strategies that might occur to China that don't reflect the knee-jerk reflex to restriction and control that Anglosphere governments have around tech.
[0] https://news.ycombinator.com/item?id=48977128