I can get that from the authoritarian Resetera point of view, but a forum discussing things doesn't depend on whether or not there's a topic about the thing considered controversial. That's only if your forum isn't for discussion, but rather for setting an agenda.
If we had a gun control discussion, that doesn't mean that someone making a gun thread, discussing guns, right above it is bad. But if you only see things through a lense in which people have to conform, then it's really bad and "contrary to the message". That's without considering the hypocrisy, like whenever someone sexualizes a man or someone fat or someone who's "acceptable" to objectify.
Didn't really see anything in that thread that seemed like wank fodder at least and from what I read since the warning there were 4 posts across 6 pages. One of them self-moderating him-/herself, when the tweet link contained NSFW things. The rest seemed more dubious, one of them was at least not what I'd consider NSFW, perhaps just tacky. I have no idea about the 2 other ones, but it certainly doesn't explain it being locked. I imagine it's more that it goes against "what we deem right" and is just "wrongthink".