Updated some key UWP references (#4727)

* Updated some key UWP references

* Updated UWP references

* Updated UWP messaging

Author: GrantMeStrength

uwp/get-started/create-uwp-apps.md

@@ -10,7 +10,11 @@ ms.localizationpriority: medium
 
 ![Build your app](images/build-your-app.png)
 
-Welcome to the [UWP platform](universal-application-platform-guide.md)! On this page, we'll point you at the right information you need to start coding the Windows apps you want to create.
+Welcome to the [UWP platform](universal-application-platform-guide.md)! 
+
+> [!NOTE]
+> If you are starting to develop Windows apps, we recommend you consider using the [Windows App SDK](/windows/apps/windows-app-sdk/), and [WinUI](/windows/apps/develop/) rather than UWP. Although still supported, UWP is not under active development. Please see [Start developing Windows apps](/windows/apps/get-started/start-here) for more information.
+
 
 Before you begin development, you should be sure to [get set up.](/windows/apps/get-started/get-set-up)
 

uwp/get-started/plan-your-app.md

@@ -11,6 +11,9 @@ ms.localizationpriority: medium
 
 On Microsoft design teams, our process for creating apps consists of five distinct stages: concept, structure, dynamics, visual, and prototype. We encourage you to adopt a similar process and have fun making new experiences for the world to enjoy.
 
+> [!NOTE]
+> It is recommended that developers who are creating new projects consider using the [Windows App SDK](/windows/apps/windows-app-sdk/) and [WinUI](/windows/apps/winui/) rather than UWP. Please see [Migrate from UWP to the Windows App SDK](/windows/apps/windows-app-sdk/migrate-to-windows-app-sdk/migrate-to-windows-app-sdk-ovw) for more details.
+
 ## Concept
 
 **Focus your app**

uwp/get-started/universal-application-platform-guide.md

@@ -2,23 +2,25 @@
 title: What's a Universal Windows Platform (UWP) app?
 description: Learn about Universal Windows Platform (UWP) apps that can run across a wide variety of devices that run Windows.
 ms.assetid: 59849197-B5C7-493C-8581-ADD6F5F8800B
-ms.date: 12/10/2021
+ms.date: 08/21/2024
 ms.topic: article
 keywords: windows 10, uwp, universal
 ms.localizationpriority: medium
 ---
 
 # What's a Universal Windows Platform (UWP) app?
 
-UWP is one of many ways to create client applications for Windows. UWP apps use WinRT APIs to provide powerful UI and advanced asynchronous features that are ideal for internet-connected devices.
+UWP is one of many ways to create client applications for Windows. 
+
+> [!NOTE]
+> If you are starting to develop Windows apps, we recommend you consider using the [Windows App SDK](/windows/apps/windows-app-sdk/), and [WinUI](/windows/apps/develop/) rather than UWP. Although still supported, UWP is not under active development. Please see [Start developing Windows apps](/windows/apps/get-started/start-here) for more information.
 
 To download the tools you will need to start creating Windows apps, see [Install tools for the Windows App SDK](/windows/apps/windows-app-sdk/set-up-your-development-environment), and then [write your first app](your-first-app.md).
 
 ## Where does UWP fit in the Microsoft development story?
 
 UWP is one choice for creating apps that run on Windows 10 and Windows 11 devices, and can be combined with other platforms. UWP apps can make use of Win32 APIs and .NET classes (see [API Sets for UWP apps](/previous-versions/mt186421(v=vs.85)), [Dlls for UWP apps](/previous-versions/mt186422(v=vs.85)), and [.NET for UWP apps](/dotnet/api/index?view=dotnet-uwp-10.0&preserve-view=true)).
 
-The Microsoft development story continues to evolve, and along with initiatives such as [WinUI](/windows/apps/winui/), [MSIX](/windows/msix/), and the [Windows App SDK](/windows/apps/windows-app-sdk/), UWP is a powerful tool for creating client apps.
 
 
 ## Features of a UWP app

uwp/get-started/your-first-app.md

@@ -12,6 +12,10 @@ ms.localizationpriority: medium
 
 Welcome to the [UWP platform](universal-application-platform-guide.md)! These tutorials will help you create your first UWP app in the language of your choice.
 
+> [!NOTE]
+> If you are starting to develop Windows apps, we recommend you consider using the [Windows App SDK](/windows/apps/windows-app-sdk/), and [WinUI](/windows/apps/develop/) rather than UWP. Although still supported, UWP is not under active development. Please see [Start developing Windows apps](/windows/apps/get-started/start-here) for more information.
+
+
 To get started, choose your favorite language.
 
 ## C# and XAML