The anime’s official Twitter announced this week that there will be a special event starring many of the show’s seiyuu — Kiiyan included — in February of next year. The first chance at tickets comes with season 3’s first blu-ray/DVD release.
More details to follow later this year.
Event: Shingeki no kyojin special event
Guests: Kaji Yuki, Ishikawa Yui, Inoue Marina, Taniyama Kishou, Kobayashi Yu, Mikami Shiori, Shimono Hiro and Kamiya Hiroshi