The review didn't spoil anything in my opinion. It really wasn't much of a review. I do agree about the trailer, it showed too much as did the clip that was shown last night on the Scream Awards but that really doesn't bother me as a spoiler junkie.
I read a review that said that much of the trailer wasn't actually in the movie. I just saw the movie. I can't remember much about the trailer to be honest, but I don't think it's going to kill it for you.
I would feel better rating this film if I saw the second one. I saw the first, liked it but didn't go crazy about it. I thought it was a bit overhyped though I liked the low key approach. As for the third, it was just okay. There were some scares, but there was also some unintended laughter in the audience too.
I thought the acting was okay, not sure if there was enough story, and I feel that this format is perhaps becoming strained. I had skipped the second one because I thought doing a sequel was stretching it, but decided to watch three because I heard how good the second one was and had some time to kill. If you like the first film you will probably find three tolerable at least. However I think it loses something because the element of surprise is gone. Also I'm not sure if the attempts to build on the mythology were satisfactory. In a way I wanted more explanation, but also knew that too much would spoil the magic.