I think it’s more that it was clearly inadvertently spoiled by a poor publishing decision. You can debate the nature of a “spoiler” but either way there is no way the author intended this. Would you agree?

Interesting take. There can’t be spoilers for real-life, somewhat obscure, events? I’d hardly call the murder of this person, however tragic, something in the common knowledge domain.

Literally the character hasn’t even been introduced yet!