Yeah, I gotta say, I’m impressed by how the non-spoiler people are reaching these conclusions with just the core arcs when I recall that a lot of the Shannon is Kanon hints really start popping up in Chiru. I know in one of the EP1 side story TIPs (something about how Gohda said he didn’t fear Beatrice to Kanon and that night, Gohda was haunted by Beatrice) strongly implied that connection between Kanon and Beatrice.
And to be fair, during the time Umineko was first released, characters like Sayo were far from common in Western media and almost nonexistent in Eastern media (and in many cases, the characters were generally portrayed as jokes), and it feels like a rather shallow motive at first (especially with how in EP7, they keep hammering that it’s Battler’s fault for coming in 1986 when really, that was just the spark that lit the powderkeg, so people are naturally gonna be like “Really? Are you serious?”. And a lot of people most likely get annoyed by the fact it’s miscommunication to create drama, because that’s an overused trope that’s rarely done right. Plus, not a lot of people have experienced that sort of wanting to wait for someone to come back. I know if my childhood friend suddenly got back in contact with me after saying she’d call back but never did after twelve years, I’d be ready to fight her.)