UPDATE: As of March 14, 2021, the third teaser has been posted—though unconfirmed, it appears to be hinting toward a Revue Starlight collaboration instead, potentially debunking some or all of the below theory-crafting. Please keep this in mind as you continue.
Building off of yesterday’s mysterious teaser, @kagakuadv has posted a second Twitter teaser that allows for more speculation about a potential upcoming reveal.
世界線変動率"0.210317%"
— 科学ADV公式 #シュタゲ10周年 (@kagakuadv) March 12, 2021
鳳凰院凶真「まさか君は、リーディング・シュタイナーを持っているのか!?」#シュタゲ pic.twitter.com/ukZRAMN2J7
In English, the Tweet’s text reads “Worldline divergence: 0.210317%. Hououin Kyouma: ‘Don’t tell me you… you possess Reading Steiner?!'”
The Tweet’s video initially shows yesterday’s divergence number before shifting to “0.170922%.” If we apply the same rule to today’s divergence number as yesterday’s, it can be interpreted as referring to the date “17/09/22,” or September 22, 2017 in Japanese date format.
シュタゲで2017/9/22と言えばこれなんだけど… https://t.co/w4P7IqQAMx
— Rowen (@r0_wen_L) March 12, 2021
The implications of this teaser are quite interesting. As pointed out by Twitter user @r0_wen_L above, September 22, 2017 was the day on which MAGES.’ Chiyomaru Shikura posted footage of Steins;Gate Elite in action for the first time.
If the new teaser’s video is meant to be taken as a callback to that event, then it may be possible that we’ll be receiving more information on the upcoming Steins;Gate 0 Elite on March 17. This would line up well with MAGES.’ upcoming SciADV release schedule, on which 0 Elite is next in line.
Note: Steins;Gate 0 spoilers below.
The Tweet’s text further supports the idea that this teaser is about Steins;Gate 0 Elite. In Steins;Gate 0, several individuals, including Mayuri’s cosplay friend Fubuki, are hospitalized due to Reading Steiner-like symptoms. This fits the tone of shock written into the teaser Tweet, though it doesn’t explain why “Hououin Kyouma” was used instead of “Okabe Rintaro,” since during the events of Steins;Gate 0, Rintaro largely casts away his Hououin Kyouma personality.
Steins;Gate 0 spoilers end here.
In the end, we do not have any official confirmation as to what these teasers are for yet, so we can only speculate right now. As always, we will strive to keep you updated as more information arises.