So what it behind the early release of the LG G2 in Korea? It is believed that LG is doing this to combat the expected July release in Korea of a Samsung Galaxy S4 sporting the Qualcomm Snapdragon 800 and offering LTE-Advanced connectivity. It just so happens that the LG Optimus G sequel also sports a Qualcomm Snapdragon 800 and is enabled for LTE-Advanced networks. The phone will also offer an edge-to-edge display and will have its buttons on the back.
No harm in giving those in Korea first crack at the device. After all, that is what we call having the home court advantage. Besides, LG will have some time to work out any bugs or problems before the August 7th event in addition to receiving some valuable feedback from Korean buyers of the phone.
source: DDaily (translated), RBMen (translated) via AndroidAuthority