Apply suggestions from code review

Co-authored-by: Jared Kirschner <85913323+jkirschner-hashicorp@users.noreply.github.com>

website/content/docs/upgrading/upgrade-specific.mdx

@@ -16,8 +16,14 @@ upgrade flow.
 
 ## Consul 1.13.x
 
-~> **Note:** If you are upgrading from `1.11`+ and have connect proxies 
-registered, upgrade directly to `1.13.1` instead of `1.13.0`.
+### Service Mesh Compatibility
+Existing Consul deployments using service mesh (i.e., containing any registered Connect proxies)
+should upgrade to **at least Consul 1.13.1**.
+
+Consul 1.13.0 contains a bug that prevents Consul server agents from restoring saved state
+on startup if the state (1) was generated before Consul 1.13 (such as during an upgrade),
+and (2) contained any Connect proxy registrations.
+This bug is fixed in Consul versions 1.13.1 and newer.
 
 ### gRPC TLS