Honestly, it depends entirely on the story. Some authors, like Brandon Sanderson, build plots where understanding the underlying mechanics of a magic system or a species' origins only enhances the awe. Knowing how a Kandra evolves in 'Mistborn' didn't ruin anything for me—it made the moments they used their abilities more tense, because I understood the stakes and limitations. I was watching for the how, not the what. For a mystery-box series where the evolution is the central twist, like certain sci-fi novels I've read, then yes, absolutely, glancing at a wiki summary could deflate the whole experience. I'd say if you're the type of reader who savors the slow unveiling of a world's rules, steer clear. If you're more fascinated by the application of established rules in clever ways, a spoiler might function more like intriguing backstory.
A friend once told me the big secret about the treecats in Weber's 'Honor Harrington' series before I got to it. I was annoyed at first, but it changed my reading. Instead of wondering what they were, I paid closer attention to the subtle cues in their interactions with humans, which became its own kind of reward. The surprise was gone, but a deeper layer of dramatic irony took its place. It's not a universal experience, but it's possible to have a spoiled fact become a different lens.