Do not directly manipulate the base class's Startup method

src/controller/tests/TestServerCommandDispatch.cpp

@@ -140,10 +140,13 @@ class DispatchTestDataModel : public CodegenDataModelProvider
     // rather than depending on the code-generated one with undefined modifications.
     CHIP_ERROR Startup(DataModel::InteractionModelContext context) override
     {
-        ReturnErrorOnFailure(DataModel::Provider::Startup(context));
-
+        ReturnErrorOnFailure(CodegenDataModelProvider::Startup(context));
         return CHIP_NO_ERROR;
     }
+
+protected:
+    // Override InitDataModel to do nothing.
+    void InitDataModel() override {}
 };
 
 class TestServerCommandDispatch : public chip::Test::AppContext

src/data-model-providers/codegen/CodegenDataModelProvider.cpp

@@ -438,8 +438,7 @@ CHIP_ERROR CodegenDataModelProvider::Startup(DataModel::InteractionModelContext
         }
     }
 
-    // Call the Ember-specific InitDataModelHandler
-    InitDataModelHandler();
+    InitDataModel();
 
     return CHIP_NO_ERROR;
 }
@@ -883,6 +882,12 @@ ConcreteCommandPath CodegenDataModelProvider::NextGeneratedCommand(const Concret
     return ConcreteCommandPath(before.mEndpointId, before.mClusterId, commandId);
 }
 
+void CodegenDataModelProvider::InitDataModel()
+{
+    // Call the Ember-specific InitDataModelHandler
+    InitDataModelHandler();
+}
+
 std::optional<DataModel::DeviceTypeEntry> CodegenDataModelProvider::FirstDeviceType(EndpointId endpoint)
 {
     // Use the `Index` version even though `emberAfDeviceTypeListFromEndpoint` would work because

src/data-model-providers/codegen/CodegenDataModelProvider.h

@@ -187,6 +187,9 @@ class CodegenDataModelProvider : public DataModel::Provider
 
     void Temporary_ReportAttributeChanged(const AttributePathParams & path) override;
 
+protected:
+    virtual void InitDataModel();
+
 private:
     // Iteration is often done in a tight loop going through all values.
     // To avoid N^2 iterations, cache a hint of where something is positioned