OK, so I hear it was ruled at worlds that Dreamwalkers can still be triggered even if only one player has a won story card. On BGG I made an incorrect response to someone asking the question, as I looked at the ruling on Opening the Limbo Gate as a precedent, (you can't play that card if the opponent doesn't have a character in their discard pile). So, what was the reasoning behind this apparent dichotomy, where it's OK for Dreamwalkers, but not for the Limbo Gate?

Color me confused, (wouldn't be the first time with this game though )