More 4.2.2 release notes updates

Author: michaelklishin

release-notes/4.2.2.md

@@ -26,6 +26,10 @@ Release notes can be found on GitHub at [rabbitmq-server/release-notes](https://
 
    GitHub issue: [#15024](https://github.com/rabbitmq/rabbitmq-server/issues/15024)
 
+ * Corrected a performance regression around metric collection that could have a meaningful impact on quorum queues.
+
+   GItHub issue: [rabbitmq/seshat#16](https://github.com/rabbitmq/seshat/pull/16)
+
  * AMQP 1.0 link error frames did not have settlement set in certain failure scenarios,
    namely when attaching a link failed due to a missing source (queue or stream).
 
@@ -43,6 +47,10 @@ Release notes can be found on GitHub at [rabbitmq-server/release-notes](https://
 
 #### Enhancements
 
+ * More efficient Khepri (metadata store) querying.
+
+   GitHub issue: [rabbitmq/khepri#349](https://github.com/rabbitmq/khepri/pull/349)
+
  * Removed a cool down delay between stream chunk redelivery attempts.
 
    GitHub issue: [#14766](https://github.com/rabbitmq/rabbitmq-server/pull/14766)