WRT posters other than the OP on a thread concerning suicide, I think it's up to each individual whether they can post without becoming too emotionally entangled and with their boundaries firmly in place.
There is sometimes an air of rubbernecking, I think though this may be true, it is more likely that people get carried away on the highly emotional charge involved in such a matter. It's easy from a cynical POV to perceive genuine concern as morbid interest when a poster's emotions are doing the talking. This does seem to cause discomfort or concern to some people but I wouldn't think it good reason to delete such threads.
Personally, I have experienced suicide (not self, obviously) and on the one hand wouldn't it be fine and dandy if such a thing didn't exist? Particularly for those of us who have felt the repercussions. This is not realistic though, it does happen and I'm impressed at the sheer number of people who do care here. I don't believe with genuine heart and mind anyone would say anything that would harm. OTOH, the danger lies in rogue posters with no conscience.
MNHQ's call I think, as the potentially liable. I'd be more than happy to support any decision, if they feel the need to make one.