There is a cluster of related stories here. Many users seem to feel that the konklone.com post is the best representative of the set, so we changed to that from
http://slackhq.com/post/103473448150/slacks-policy-update, and gave it a neutral title.
We're working on a system for grouping related stories together, but don't know yet when it will be ready. In the meantime, we merge threads manually, and you have to fish through the comments looking for context (like what the previous url was, why it was changed, and so on). That's not great, but see the first sentence of this paragraph.
There were a couple of borderline calls here: first, whether there are two significant stories that deserve to be on the front page, or just one (I'd argue just one, but it's not obvious); second, which of the two urls should be on the front page. Initially we chose the one that had been submitted earlier and had the larger discussion. Based on user feedback, we've flipped to the other.
I'm marking this subthread off-topic now, so it doesn't stay at the top and make the thread be about HN story merging policy.