Curate, connect, and discover
To me the Chosen reveal is compelling not because we now know that Chosen did bad things (we been knew) but because this is the first time in the entire series that Chosen has actually been narratively positioned as an antagonist.
In the past, he’s always been the one we’re meant to root for for, regardless of his actions. This is the first time the story has set him up in a role that has him opposing the characters we’re meant to root for.
The emotion comes not from the reveal that he did bad things, but from the reveal that, at least with how he is framed in this appearance, we are meant to root against him.