It would be horribly inappropriate for China's military leadership to consider any of this type of propaganda from the west. Whatever the source or the intention. If the F-35 is limited in usefulness against a mainland reunification effort, then great. It probably isn't useless and definitely should not be regarded as such. Breeds some sort of complacency and arrogance.
The US is by all reasonable estimates, very close to refining their 6th gen platform/s. Warfare is constantly changing. While China today may have decent enough A2AD against US CBGs and assets positioned all around China, even possibly against USN submarines (since it something China refuses to even hint at how apart from hinting they can detect submarines with certainty). This defense may not last because the US is constantly trying to get the better of it and when they do they will go kinetic the moment they are sure.
China's SCS strategy is built on the backbone of PLA reaching parity with US military and then exceeding it in all conventional domains and exceeding it in how it runs and wins conventional warfare. It must also guarantee MAD regardless of what technologies may exist to repel or counter Chinese efforts at MAD. Without all three, China can forget about guaranteeing SCS, itself a basis for ensuring western pacific security, trade routes, keeping USN at a distance, and if there are to be any last resort military option for reunification of China in case Taiwanese politics go with declaring independence or worse.
No F-35 or US military news (unless it is positive developments that threaten China) should ever be considered, particularly when it comes from the west itself. Because it changes nothing in terms of PLA's eventual goal. These all need to be achieved against the clock.