It's a good question and I don't have the answer, beyond that there is a lot of value to it; if we lost Slack, it'd be a big problem, even though the board works really well.

There is something to being able to just randomly vent or muse on Slack and have a conversation organically pick up --- or not pick up, it's the optionality that's maybe important? Whereas, every message board post feels like an appeal for feedback and discussion, and so requires just a bit more activation energy.