Idea: A slack bot that searches for questions and answers and creates a wiki out of the scraped information.
It's not that it shouldn't be, but that it probably won't be when it should. My company uses HipChat and not Slack, but ever since we first adopted it about 4 years ago I have been preaching that our in-house technical support staff use its search function before asking the developers for help. Maybe 10% of them do, if I'm being generous. The rest think their issue is unique and requires immediate one-on-one developer attention.
We also have an in-house wiki that doesn't get consulted as often as it should. I spend at least half a day documenting, from a end-user perspective, every project I complete on our wiki and still find myself repeating what I've written in a one-on-one chat on a daily basis.