the lgbt thread made the impression that they where there to baitpost and push their ideology. 4chan is full of a bunch of contrarian cryptofascists among the original but now occasional liberal. Even if the lgbt thread poster genuinely meant no tumblr tier harm, they are going to get a paddlin and their thread saged.
The only thing this thread did was make it more specific to one appeal type to cut down on inner group conflict (this, incidentally, is also why /lgbt/ works as well) and use communication standards consistent with the tone of the board culture, communicating their authenticity for being regular mlp visitors.
There's a lot of communication even in text, and especially when there isn't communication from one party doesn't mean nothing is communicated to the other.