Logistically & mobility wise it make all the sense to hold drills as close as possible near the target.
I'm hearing from my Chinese sources there might by an imminent invasion but not confirmed yet.
Holding drills close to the target could give away methods to be employed during the actual war.
Considering the vast stretchers of deserts and mountains in China, the PLA could hold less noticeable Brigade sized exercises all over China. Where each brigade simulates one slice of an objective area issuing Y-20 and Y-9 based Paratroopers, Z-10, Z-20 and AC-313A based Air Cavalry and hovercrafts based troops to simulate amphibious landings. All these exercises could be “tied together digitally” to simulate one big invasion, even though it is being carried out of over 50-100 training grounds.
Speaking of logistics, an indication China is mass producing large hovercrafts?
A few hundred large hovercrafts could also be used for commercial purposes until and invasion is ordered. Even with its drawbacks, it offers the PLA greater element of surprise and if an invasion with a beachhead are secured, intervention by foreign powers maybe less likely.