Anime News Network's coverage of Anime Expo 2019 is sponsored by Yen Press.
The official Twitter account for the Sword Art Online anime franchise began streaming a new English-subtitled teaser video for the Sword Art Online: Alicization – War of Underworld anime on Saturday. The video streamed at Anime Expo earlier on Saturday. The anime will premiere this October.
— アニメ ソードアート・オンライン 公式 (@S.A.O_anime) July 7, 2019
Sword Art Online: Alicization premiered in Japan on October 6 and is streaming on Crunchyroll, Hulu, and FunimationNOW. The series is adapting the entire "Alicization Arc" of Reki Kawahara's original novels and will air for four cours, or four quarters of a year. The first two cours aired from October to March.
Manabu Ono (Horizon in the Middle of Nowhere, Saki, The Asterisk War) is directing the anime at A-1 Pictures. Sword Art Online the Movie: Ordinal Scale animation directors Gou Suzuki and Tomoya Nishiguchi are joining Shingo Adachi for the character designs. Yuki Kajiura is returning to compose the music.
Source: Sword Art Online anime's Twitter account