We don't stop communicating since we unslacked though. Instead we now moved discussions more to Github PRs+issues and Basecamp. So its still possible to read up, but it feels more structured around certain tasks.
This might be the key to whatever becomes the big "Slack-killer", assuming one comes around: Real-time-ish chat that with respects to workflow and UI/UX are structured around action-items (be they user stories, support tickets, or deployment artifacts), easily searchable, with support for taxonomy.