Default to MSAL authentication 🚀 (#237920)

Here we go. Ref https://github.com/microsoft/vscode/issues/178740

extensions/microsoft-authentication/package.json

@@ -102,7 +102,7 @@
         "properties": {
           "microsoft-authentication.implementation": {
             "type": "string",
-            "default": "classic",
+            "default": "msal",
             "enum": [
               "msal",
               "classic"
@@ -111,10 +111,9 @@
               "%microsoft-authentication.implementation.enumDescriptions.msal%",
               "%microsoft-authentication.implementation.enumDescriptions.classic%"
             ],
-            "description": "%microsoft-authentication.implementation.description%",
+            "markdownDescription": "%microsoft-authentication.implementation.description%",
             "tags": [
-              "onExP",
-              "preview"
+              "onExP"
             ]
           }
         }

extensions/microsoft-authentication/package.nls.json

@@ -3,9 +3,15 @@
 	"description": "Microsoft authentication provider",
 	"signIn": "Sign In",
 	"signOut": "Sign Out",
-	"microsoft-authentication.implementation.description": "The authentication implementation to use for signing in with a Microsoft account.",
+	"microsoft-authentication.implementation.description": {
+		"message": "The authentication implementation to use for signing in with a Microsoft account.\n\n*NOTE: The `classic` implementation is deprecated and will be removed, along with this setting, in a future release. If only the `classic` implementation works for you, please [open an issue](command:workbench.action.openIssueReporter) and explain what you are trying to log in to.*",
+		"comment": [
+			"{Locked='[(command:workbench.action.openIssueReporter)]'}",
+			"The `command:` syntax will turn into a link. Do not translate it."
+		]
+	},
 	"microsoft-authentication.implementation.enumDescriptions.msal": "Use the Microsoft Authentication Library (MSAL) to sign in with a Microsoft account.",
-	"microsoft-authentication.implementation.enumDescriptions.classic": "Use the classic authentication flow to sign in with a Microsoft account.",
+	"microsoft-authentication.implementation.enumDescriptions.classic": "(deprecated) Use the classic authentication flow to sign in with a Microsoft account.",
 	"microsoft-sovereign-cloud.environment.description": {
 		"message": "The Sovereign Cloud to use for authentication. If you select `custom`, you must also set the `#microsoft-sovereign-cloud.customEnvironment#` setting.",
 		"comment": [

extensions/microsoft-authentication/src/extension.ts

@@ -35,8 +35,8 @@ function shouldUseMsal(expService: IExperimentationService): boolean {
 	}
 
 	Logger.info('Acquired MSAL enablement value from default. Value: false');
-	// If no setting or experiment value is found, default to false
-	return false;
+	// If no setting or experiment value is found, default to true
+	return true;
 }
 let useMsal: boolean | undefined;