Connections is an enterprise feature. This connector is marked Coming soon.
Enterprise
Slack
A connector listed in Settings › Connections. It is coming soon and cannot be connected yet.
Slack is listed in Settings › Connections and says Coming soon. It cannot be connected today, and its row carries no controls.
When it lands, Slack will be a kind of source, so its documents will come into the workspace and be curated by the same Document scan as every other source.