Agreed with all the above @charlesmartin and @alexarje. However, I’m wondering if it’s worth keeping the Slack workspace as an archive, or if it’s better to export the conversations and archive them somewhere. Maybe even process the data removing all the faff that nobody reads to read again.
Re: reaching out to those involved in good discussions, that would be a great idea but only the thought of it makes me think that it would require an enormous amount of time. Maybe we should find a way for the community to do this, and we review the requests? We could ask the community to go through the Slack Workspace (or archived equivalent) and propose topics that should be ported into Discourse. A reviewing team could then review these proposals and approve/reject requests.