Chinese Fireworks on the 4th of July (info on carrier targeting missile, too)
But even that isn’t why the Pentagon has both eyes focused on this exercise. The reason this exercise has many concerned is that China may test a DF-21D anti-ship ballistic missile. Andrew Erickson noted in his latest article that China has appeared to be getting close to their first DF-21D test.
Given the nature of the reported training, it is at least theoretically possible that it might incorporate tests by the Second Artillery involving missiles launched from land. Open source background and timelines on Chinese anti-ship ballistic missile (ASBM) development–as offered in my China ASBM Analysis and Archive post–suggest that this could even include some form of ASBM tests, based on China’s current state of ASBM development and stated desire to demonstrate the ability to threaten carrier strike groups (CSGs).