According to a new info, the retirement will be in June
"The final elephant walk of the F-4E Phantom, Korea's former main fighter jet, which is scheduled to be retired in June, took place at the Air Force Suwon Base on the 8th."
"The Phantom was the Air Force's main fighter aircraft until the KF-16 entered service in 1994. The Air Force has so far operated about 220 aircraft, including the F-4E, an improved version of the F-4D, and the reconnaissance aircraft RF-4C. Currently, most of the Phantoms have been retired and only about 10 remain, and these are also scheduled to end their activities in June"
South Korea’s F-4E Phantom II performed its final live-fire exercise after 55 years of service and will be retired on June 7, along with the AGM-142 “Pop-eye” missiles.