As per aspnet#325, reference module.hot directly instead of via a local var, because Webpack does static analysis that looks for this

SteveSandersonMS · SteveSandersonMS · commit 2ba5a0ac930a · 2016-09-20T16:51:50.000+01:00
diff --git a/templates/Angular2Spa/ClientApp/boot-client.ts b/templates/Angular2Spa/ClientApp/boot-client.ts
@@ -5,10 +5,9 @@ import { AppModule } from './app/app.module';
 import 'bootstrap';
 
 // Enable either Hot Module Reloading or production mode
-const hotModuleReplacement = module['hot'];
-if (hotModuleReplacement) {
-    hotModuleReplacement.accept();
-    hotModuleReplacement.dispose(() => { platform.destroy(); });
+if (module['hot']) {
+    module['hot'].accept();
+    module['hot'].dispose(() => { platform.destroy(); });
 } else {
     enableProdMode();
 }
