It isn’t inconceivable but it is highly unlikely that China was able to design and manufacture their own chips. Chip manufacturing requires multiple inputs from a supply chain that is thousands of vendors long. These vendors are usually small and specialize in making a single component of what goes into the chip making process and there normally aren’t other companies that also duplicate that item. We haven’t even gone into the specialties needed to design the chips or produce the foundries needed to make them.
There is no single country capable of completing every step of the process from design to tooling to manufacturing inputs. Japan, Taiwan, Netherlands and the US are all major players for high end chips but no single one of them can complete the entire process on their own. The Biden administration managed to get all of these players to agree to lock China out of the mid to high end chip market. Biden also made it illegal for IS Nationals on pain of loosing citizenship to help China design chips. So China not only doesn’t have the expertise to call on, they are also locked out of this ecosystem of vendors from these countries.
Could China do it… possibly they’ve thrown a lot of money and have a lot of failed chip companies to show for it. One of the established tech Chinese majors may have pulled it off.
More than likely they completed work on a chip that was in the finishing stages and had the majority of inputs on hand before the embargo was enacted. I’d wait and see if they start pumping out a large volume of these chips then I’d give them credit for a major accomplishment on manufacturing. If they can continue to design new chips without any foreign help then they will have pulled it off in my book. Until then I’m going to have serious doubts.