“It’s probably Matt Mercer’s fault.”
TBH the whole "I ran/played this adventure before" stories more often come with "This is how I tried to help the DM" in my circles... I have 2 raven loft examples were we TOTALLY used out of game info to make sure someone did something that we knew the adventure needed to be fun and kept going... no 3 I forgot I am almost playing in curse of strahd once a month (we meet 4 times in the last 7 months so it's easy for me not to count it).
While I'm 100% with @iserith and @Charlaquin about metagaming, I'm also anti-jerk. (The solution to jerks is to avoid playing with them, not impose layers of rules.). While I will happily burn trolls with a 1st level character without a second thought, if there's a new player at the table I might instead have my character freak out and shout "run away!" Not because of any kind of anti-metagaming philosophy, but to try to give that new player the experience I remember.
Likewise if I'm in a published adventure that I know, but the other players don't know I know (I always tell the DM), I will sometimes help keep the adventure exciting by intentionally making bad choices.
But if everybody at the table has some information? I truly don't understand the point of all of us pretending we don't.