The problem is that subreddit's users took it as an attack on one of their own.
So there is already a group of users who frequent places which dox and harass others that think suicidewatch is out to get them.
My post, at least I hoped, would get at least a few of them to realize that it their anger was all about a lie and was just one of their users trolling and mods trying to get them angry about the enemy. Hopefully getting them to not harass the sub which they are inclined to do.
If it was an actual post to
/r/suicidewatch
I wouldn't have linked it. This user tried to troll them to feel even more important as he left reddit and doing so got a whole bunch of crazy doxing users upset with
/r/suicidewatch.
As for when he said he was afraid his users would harass them because of the post. If the sub is so toxic that you can't link to a suicide prevention sub without large scale brigading the admins need to nuke that shit from orbit.