Personally speaking, this is too sudden and sad. I'll cut the news short:

Juwon received an immensely great opportunity as an actor and wanted to grasp the chance. Unfortunately, AA's schedule was too tight, so the group took the difficult decision to let him go. 

His last song with Double A will be entitiled "2nite 3X." Juwon will still be under Wellmade Ent. so we hope that you all support him! 

Source: Naver