diff --git a/sdk/eventgrid/azure-eventgrid/CHANGELOG.md b/sdk/eventgrid/azure-eventgrid/CHANGELOG.md
index 5b7a9b0790dd..375754865e1e 100644
--- a/sdk/eventgrid/azure-eventgrid/CHANGELOG.md
+++ b/sdk/eventgrid/azure-eventgrid/CHANGELOG.md
@@ -1,14 +1,10 @@
 # Release History
 
-## 4.20.1 (Unreleased)
+## 4.21.0 (2024-11-19)
 
 ### Features Added
 
-### Breaking Changes
-
-### Bugs Fixed
-
-### Other Changes
+- Added new enum values to `SystemEventNames` related to Azure Resource Notifications.
 
 ## 4.20.0 (2024-06-12)
 
diff --git a/sdk/eventgrid/azure-eventgrid/azure/eventgrid/_legacy/_event_mappings.py b/sdk/eventgrid/azure-eventgrid/azure/eventgrid/_legacy/_event_mappings.py
index 59fbfed265e6..ed9f5e4d91e3 100644
--- a/sdk/eventgrid/azure-eventgrid/azure/eventgrid/_legacy/_event_mappings.py
+++ b/sdk/eventgrid/azure-eventgrid/azure/eventgrid/_legacy/_event_mappings.py
@@ -424,6 +424,10 @@ class SystemEventNames(str, Enum, metaclass=CaseInsensitiveEnumMeta):
 
     ResourceDeleteSuccessName = "Microsoft.Resources.ResourceDeleteSuccess"
 
+    ResourceNotificationsContainerServiceEventResourcesScheduledEventName = (
+        "Microsoft.ResourceNotifications.ContainerServiceEventResources.ScheduledEventEmitted"
+    )
+
     ResourceNotificationsHealthResourcesAnnotatedEventName = (
         "Microsoft.ResourceNotifications.HealthResources.ResourceAnnotated"
     )
diff --git a/sdk/eventgrid/azure-eventgrid/azure/eventgrid/_version.py b/sdk/eventgrid/azure-eventgrid/azure/eventgrid/_version.py
index 9462cc312640..69b8a4d0e5df 100644
--- a/sdk/eventgrid/azure-eventgrid/azure/eventgrid/_version.py
+++ b/sdk/eventgrid/azure-eventgrid/azure/eventgrid/_version.py
@@ -6,4 +6,4 @@
 # Changes may cause incorrect behavior and will be lost if the code is regenerated.
 # --------------------------------------------------------------------------
 
-VERSION = "4.20.1"
+VERSION = "4.21.0"
diff --git a/sdk/eventgrid/azure-eventgrid/azure/eventgrid/models/_patch.py b/sdk/eventgrid/azure-eventgrid/azure/eventgrid/models/_patch.py
index 8b9dcb1760cb..a552fe3c3125 100644
--- a/sdk/eventgrid/azure-eventgrid/azure/eventgrid/models/_patch.py
+++ b/sdk/eventgrid/azure-eventgrid/azure/eventgrid/models/_patch.py
@@ -15,6 +15,7 @@
 
 DataType = TypeVar("DataType")
 
+
 class ReceiveDetails(InternalReceiveDetails, Generic[DataType]):
     """Receive operation details per Cloud Event.
 
diff --git a/sdk/eventgrid/azure-eventgrid/samples/namespace/async_samples/sample_publish_cncf_events_async.py b/sdk/eventgrid/azure-eventgrid/samples/namespace/async_samples/sample_publish_cncf_events_async.py
index d8b641ddf627..24bf463e44a3 100644
--- a/sdk/eventgrid/azure-eventgrid/samples/namespace/async_samples/sample_publish_cncf_events_async.py
+++ b/sdk/eventgrid/azure-eventgrid/samples/namespace/async_samples/sample_publish_cncf_events_async.py
@@ -34,7 +34,11 @@ async def publish():
         await client.send(
             [
                 CloudEvent(
-                    attributes={"type": "cloudevent", "source": "/cncf/cloud/event/1.0", "subject": "testing-cncf-event"},
+                    attributes={
+                        "type": "cloudevent",
+                        "source": "/cncf/cloud/event/1.0",
+                        "subject": "testing-cncf-event",
+                    },
                     data=b"This is a cncf cloud event.",
                 )
             ]
diff --git a/sdk/eventgrid/azure-eventgrid/swagger/_constants.py b/sdk/eventgrid/azure-eventgrid/swagger/_constants.py
index 0a2cfc4503c7..14e790d924c2 100644
--- a/sdk/eventgrid/azure-eventgrid/swagger/_constants.py
+++ b/sdk/eventgrid/azure-eventgrid/swagger/_constants.py
@@ -23,6 +23,7 @@
     "https://raw.githubusercontent.com/Azure/azure-rest-api-specs/main/specification/eventgrid/data-plane/Microsoft.Resources/stable/2018-01-01/Resources.json",
     "https://raw.githubusercontent.com/Azure/azure-rest-api-specs/main/specification/eventgrid/data-plane/Microsoft.ResourceNotifications/stable/2018-01-01/HealthResources.json",
     "https://raw.githubusercontent.com/Azure/azure-rest-api-specs/main/specification/eventgrid/data-plane/Microsoft.ResourceNotifications/stable/2018-01-01/Resources.json",
+    "https://raw.githubusercontent.com/Azure/azure-rest-api-specs/main/specification/eventgrid/data-plane/Microsoft.ResourceNotifications/stable/2018-01-01/ContainerServiceEventResources.json",
     "https://raw.githubusercontent.com/Azure/azure-rest-api-specs/main/specification/eventgrid/data-plane/Microsoft.ServiceBus/stable/2018-01-01/ServiceBus.json",
     "https://raw.githubusercontent.com/Azure/azure-rest-api-specs/main/specification/eventgrid/data-plane/Microsoft.SignalRService/stable/2018-01-01/SignalRService.json",
     "https://raw.githubusercontent.com/Azure/azure-rest-api-specs/main/specification/eventgrid/data-plane/Microsoft.Storage/stable/2018-01-01/Storage.json",
diff --git a/sdk/eventgrid/azure-eventgrid/swagger/postprocess_eventnames.py b/sdk/eventgrid/azure-eventgrid/swagger/postprocess_eventnames.py
index 842afcc14797..8ce472bbbc09 100644
--- a/sdk/eventgrid/azure-eventgrid/swagger/postprocess_eventnames.py
+++ b/sdk/eventgrid/azure-eventgrid/swagger/postprocess_eventnames.py
@@ -3,7 +3,7 @@
 import warnings
 import sys
 from urllib.request import urlopen
-from azure.eventgrid._generated import models
+from azure.eventgrid._legacy._generated import models
 from _constants import files, backward_compat, additional_events, EXCEPTIONS, NAMING_CHANGES