Ring of Honor sent out the following tweet announcing Samoa Joe for their June 20th event:
Last week he confronted @FightOwensFight 6/20 @SAMOAJOE Returns! #Aftershock. Get ur tix now http://t.co/WClaU4jm47 pic.twitter.com/qtjGCfWfFp
— ROH Wrestling (@ringofhonor) May 26, 2015
As noted earlier, Joe has a unique contract that allows him to work for both WWE and non-WWE wrestling events.