As it happens, the current number-two article on HN is about a similar consequence of Chinese export controls--a car manufacturer developing electric motors that do not use rare earths:
Realpolitik in action. Great powers just impose export controls because they know they can and they think it would be beneficial to the nation.
Yeah because they’re just using electromagnets. Those motors are not better than the rare earth ones.
The incentives around OSS become stronger the further down in the list of market leaders a company is. The #1 company has no particular incentive to push open software apart from a belief that the market is going to be come commoditised anyway. But the 2nd or 3rd largest player has actual incentives to break the market up and remove software quality as a consideration. No #10 may as well not bother with a proprietary option since if they make it a software quality battle they're going to lose each customer 9 times anyway.
Just because the Chinese are running export controls in one market doesn't mean that they're going to close of access to AI. They might, but each market should be considered in isolation.