diff --git a/server/src/main/java/org/opensearch/cluster/metadata/MetadataCreateIndexService.java b/server/src/main/java/org/opensearch/cluster/metadata/MetadataCreateIndexService.java
index 6812a53be64f7..ce8270c858525 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/MetadataCreateIndexService.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/MetadataCreateIndexService.java
@@ -1469,7 +1469,9 @@ public void validateIndexSettings(String indexName, final Settings settings, fin
         throws IndexCreationException {
         List<String> validationErrors = getIndexSettingsValidationErrors(settings, forbidPrivateIndexSettings, indexName);
         validateIndexReplicationTypeSettings(settings, clusterService.getClusterSettings()).ifPresent(validationErrors::add);
-        validateAutoExpandReplicaConflictInRequest(settings).ifPresent(validationErrors::add);
+        if (FeatureFlags.isEnabled(FeatureFlags.READER_WRITER_SPLIT_EXPERIMENTAL_SETTING)) {
+            validateAutoExpandReplicaConflictInRequest(settings).ifPresent(validationErrors::add);
+        }
         validateErrors(indexName, validationErrors);
     }
 
diff --git a/server/src/main/java/org/opensearch/cluster/metadata/MetadataUpdateSettingsService.java b/server/src/main/java/org/opensearch/cluster/metadata/MetadataUpdateSettingsService.java
index f2753c6d7994c..de099f0c8551f 100644
--- a/server/src/main/java/org/opensearch/cluster/metadata/MetadataUpdateSettingsService.java
+++ b/server/src/main/java/org/opensearch/cluster/metadata/MetadataUpdateSettingsService.java
@@ -231,10 +231,12 @@ public ClusterState execute(ClusterState currentState) {
                             metadata.getSettings()
                         ).ifPresent(validationErrors::add);
 
-                        validateAutoExpandReplicaConflictInRequest(normalizedSettings).ifPresent(validationErrors::add);
-                        validateAutoExpandReplicaConflictWithIndex(normalizedSettings, metadata.getSettings()).ifPresent(
-                            validationErrors::add
-                        );
+                        if (FeatureFlags.isEnabled(FeatureFlags.READER_WRITER_SPLIT_EXPERIMENTAL_SETTING)) {
+                            validateAutoExpandReplicaConflictInRequest(normalizedSettings).ifPresent(validationErrors::add);
+                            validateAutoExpandReplicaConflictWithIndex(normalizedSettings, metadata.getSettings()).ifPresent(
+                                validationErrors::add
+                            );
+                        }
                     }
 
                     if (validationErrors.size() > 0) {