If what you're saying were the case, that anything other than downplaying the fan issue was grounds for censorship, it'd be happening to other people. The whole thread would have to go. Surely, there's something else at play here. Possibly unknowingly violating some obscure forum rule or something is a more likely scenario i would think. That or maybe someone maliciously reported your comment like Jerryk said. If you linked to another forum on that forum (like linking to the fan noise thread here), that also may have been a breaking of a rule.
Another possibility is maybe one of your posts in the thread came off too combative? I've seen some posts on some of those issue threads get pretty heated, especially with issues that not everyone experiences the same. They end up becoming arguments about whether someone actually is or isn't having the issue. I could be reading too much into it, but going off of what you're saying here and how you're wording it, it sounds like there's some residual frustration from the discussion you were having in that thread and that it did get argumentative. If keeping things civil is a rule on the forum, then i could see how getting a little too passionate with your presentation of the facts would get some of your comments removed.