docs: only mention what changed with drain

website/source/docs/upgrade/upgrade-specific.html.md

@@ -57,23 +57,12 @@ Node draining via the [`node drain`][drain-cli] command or the [drain
 API][drain-api] has been substantially changed in Nomad 0.8. In Nomad 0.7.1 and
 earlier draining a node would immediately stop all allocations on the node
 being drained. Nomad 0.8 now supports a [`migrate`][migrate] stanza in job
-specifications to control how many allocations may be migrated at once. For
-service jobs with a `count > 1` the default migrate stanza will be used:
+specifications to control how many allocations may be migrated at once and the
+default will be used for existing jobs.
 
-```hcl
-  migrate {
-    max_parallel     = 1
-    health_check     = "checks"
-    min_healthy_time = "10s"
-    healthy_deadline = "5m"
-  }
-```
-
-The old drain behavior made it impossible to drain multiple nodes at once
-without risking service outages and lots of churn as draining allocations could
-be placed on nodes that are about to be drained. Nomad 0.8's drain behavior is
-intended to fix these issues and offer both job authors and cluster operators
-more control over drains.
+The `drain` command now blocks until the drain completes. To get the Nomad
+0.7.1 and earlier drain behavior use the command: `nomad node drain -enable
+-force -detach <node-id>`
 
 See the [`migrate` stanza documentation][migrate] and [Decommissioning Nodes
 guide](/guides/node-draining.html) for details.