Update Gerrit v2.16.18 release notes

Change-Id: I7449fc0311e5ed73b9f9f87456a6cbbcac71e412
diff --git a/pages/site/releases/2.16.md b/pages/site/releases/2.16.md
index 0177ee1..88c40e1 100644
--- a/pages/site/releases/2.16.md
+++ b/pages/site/releases/2.16.md
@@ -609,31 +609,45 @@
 
 ## Bugfix Releases
 
-### 2.16.18
+### 2.16.18 (In development)
 
 * Breaking Changes
 
-  * Minimum git version is increased to 2.15.0 for the `commit-msg` hook.
+  * [Issue 12527](https://bugs.chromium.org/p/gerrit/issues/detail?id=12527):
+  Remove support for discontinued Elasticsearch v5.6, v6.0 up to v6.4.
 
-    The `commit-msg` hook now uses the `--where` option on the
-    `git-interpret-trailers` command. This option was introduced in
-    git version 2.15.0.
+  * Plugin API: Remove deprecated draft workflow methods, remove deprecated ChangeApi.getEdit method.
+
+  * Metrics: make cache disk stat metric computation optional.
+
+    Disable the cache disks stat metrics for persistent caches by default
+    because is a very expensive and can block a thread for several minutes on
+    larger installations.
+
+* New Features
+
+  * Make legacy version of the commit-msg hook available
+
+    Make the older version of the commit-msg hook from gerrit 2.15.x,
+    which does not use git-intepret-trailers, available from the site so that
+    users who have an older client can download it.
 
 * Bug Fixes
 
-  * [Issue 12546](https://bugs.chromium.org/p/gerrit/issues/detail?id=12546):
-  Fix `Change-Id` being inserted at end of trailers instead of start.
-
-    The `commit-msg` hook inserted the `Change-Id` at the end of the trailers,
-    which could result in other trailers such as `Signed-off-by` being added
-    multiple times.
-
   * Fix handling of ambiguous name in `visibleto` search predicate
 
     If the `visibleto` search predicate was used with a display name that
     resolved to more than one account, the first account in the result was
     arbitrarily used. Now, this case will result in an error.
 
+  * [Issue 11625](https://bugs.chromium.org/p/gerrit/issues/detail?id=11625):
+  Avoid multiple notifications for existing reviewers.
+
+* PolyGerrit UI Fixes
+
+  * [Issue 12385](https://bugs.chromium.org/p/gerrit/issues/detail?id=12385):
+  Fix for Memory leak in gr-plugin-endpoints.
+
 * Library Upgrades
 
   * Upgrade rules_closure to forked version
@@ -641,6 +655,23 @@
     This fixes the "-parameters is not supported for target value 1.7. Use 1.8 or later."
     warning when building. See [PR 478](https://github.com/bazelbuild/rules_closure/pull/478).
 
+  * [Issue 12448](https://bugs.chromium.org/p/gerrit/issues/detail?id=12448):
+  Switch to using no-AOP Guice distribution
+
+    Switch to using Guice without AOP feature altogether: guice-x.y.z-no_aop.jar for
+    supporting more easily newer JDK versions.
+
+* Security Fixes
+
+  * [Issue 8952](https://bugs.chromium.org/p/gerrit/issues/detail?id=8952):
+  Do not require explicit "Push Tag" rights to refs/tags/* for pushing an annotated tag over HTTPS.
+
+* Replication plugin fixes
+
+  * Improve logging of why a project or ref is not replicated.
+
+  * Documentation: clarify the limitations of gerrit+ssh in v2.16.
+
 ### 2.16.17
 
 * Breaking Changes