Suga was not present at Jin's military discharge due to his own scheduled solo tour in Japan. He had previously announced his "D-DAY" tour, which began on April 26th, 2023, in Osaka, Japan. The tour was planned before Jin's enlistment, and Suga had to fulfill his professional commitments.
This is a common occurrence for members of popular groups, as they often have individual projects and schedules that conflict with each other. While it's understandable that fans were disappointed by Suga's absence, he likely celebrated Jin's return in private.
It's important to remember that all seven members of BTS have expressed their strong bond and support for one another. While they may not always be able to be physically present for each other's milestones, their love and respect for each other is undeniable.
