Maybe, if you know you need to avoid spoilers. But if you didn't know you were likely to be playing it then it was mentioned in most reviews. And the reason that's such an issue is the adventure lets the PCs fairly easily uncover the Traitor if they choose to investigate at all, it even has an NPC come up to the party and say they are suspicious of X, but then it doesn't know what to do after they are exposed.
dms looking at that mini hoping for something they can use to represent the disguised character in play:
Whether or not it’s scary really comes down to the descriptive powers of the DM. There is nothing inherently horror about D&D being hazardous to the health of PCs. “Shocking realisations*” are more on theme for the Gothic subgenre, and Ravenloft (original) spoiled those on the cover.
And this is why. I agree that the sense of control (or lack thereof) is key to making it horror. But, not feeling like you’re in control of whether your character lives or dies makes for a poor D&D playing experience in my opinion. To each their own of course, but personally I want my players to feel in control of their characters’ fates, even in an ostensibly horror-flavored campaign. Ideally a Ravenloft campaign should endeavor to walk the fine line between horror and fantasy, playing with the notion that whatever control you may have is tenuous at best. But, in my experience when the players feel like they’ve lost control, they struggle to maintain investment, and that’s when a game can spiral into chaos.
