changelog: update missing entry (#14906)

* changelog: update missing entry

* changelog: add ILM release note

changelogs/8.17.asciidoc

@@ -13,6 +13,7 @@ https://github.com/elastic/apm-server/compare/v8.16.0\...v8.17.0[View commits]
 
 - Clear scroll after completing scroll requests {pull}14551[14551]
 - Surface config parsing error under EA managed mode by logging and marking EA input unit as failed {pull}14574[14574]
+- Remove unnecessary hot reload under EA managed mode when apm tracing config is nil {pull}14865[14865]
 - The mappings are updated to disable date_detection for all APM data streams.
   The change is applied through https://github.com/elastic/elasticsearch/pull/116995[elasticsearch#116995]
 
@@ -26,4 +27,9 @@ https://github.com/elastic/apm-server/compare/v8.16.0\...v8.17.0[View commits]
 ==== Intake API Changes
 
 [float]
-==== Added
+==== Added
+
+- In 8.15 the default lifecycle management was switched to leverage DSL instead of ILM.
+  This change was potentially interruptive for several use cases, and therefore is reverted in 8.17.
+  From 8.17 onwards ILM is again the default lifecycle management configuration for the apm data management setup.
+  The change is applied through https://github.com/elastic/elasticsearch/pull/115687[elasticsearch#115687]