If Murican military planes can venture this close to the Chinese coastline (and much closer even) on a constant basis and with impunity, what's stopping them from (secretly) mining the entire Chinese coastline with discreet methods over the past years and decades, and going into the coming years?
Basically attempting a repeat of how they starved Japan towards the end of WW2, that is.
This, apart from LO missile swarms, are among a series of worrying developments which could significantly impact China's military power projection into the WestPac in the future.
The American planes didn't fly in secret or whatever. China clearly allowed it. So I don't think this is proof that American planes can mine China's coastline in secret whenever it wants to. The article even says that we had to destroy our own equipment to prevent it from falling into China's hands.