That is not what your link says, but regardless of the details, Chinese companies are free to do whatever they want if they have no interest in exporting their products outside of China. Many do not care about markets outside of China. It is unlikely that China will drop all other ISAs in favor of RISC-V, especially since x86 and ARM are just as dominant in China as they are in other countries.
You should not reason about China as a monolithic entity. China has a population of 1.4 billion people. Some look outward while others look inward. Those looking outward are interested in RISC-V for certain things since it is not subject to U.S. export controls (so far).
China is unlikely to move away from x86 and ARM internally even in a 10 year span. The only way that would happen is if RISC-V convinces the rest of the world to move away from those architectures in such a short span of time. ISA lock-in from legacy software is a deterrent for migration in China just as much as it is in any other country.
By the way, RISC-V is considered a foreign ISA in China, while the MIPS-derived LoongArch is considered (or at least marketed as) a domestic ISA. If the Chinese make a push to use domestic technology, RISC-V would be at a disadvantage, unless it is rebranded like MIPS was.
But that is the thing China wants to move on to exporting high value items themselves instead of manufacturing it for others and letting them take most of the profits. The bans and stuff has just started but this will result in China moving towards RISC-V the same way export of latest node tech has resulted in China doing it themselves and rapidly catching up. If you read my original comment what I said was over the next decade China will move away from Arm and x86 for RISC-V. It takes years to plan and built devices 5-6 years from now we will find out what I am predicting comes true or not.