I just might add such a rule one of these days. Not to enforce a torrent link (I very rarely torrent new eps anyway) and like enkoujin said, due to DMCA it's forbidden to post the link in HxH, but to state that the first person discussing a new episode must first declare it in the beginning of their post (in any clear way, just an episode number would suffice).
Otherwise this is certainly an annoying problem. Some people watch eps via streaming or other means and start to discuss eps before HS is out (which usually is the first DL option). If such a person doesn't in any way announce they are speaking about the fresh episode in the beginning of the post but instead first type in a spoiler, there are high chances for unsuspecting viewers to acquire unwanted info. That has certainly happened to me.
I'm not surprised Y considers this the worst idea considering that over the years I've been spoiled by his irc comments time after time. The man lives for spoilers.