updating AKSe release notes for v0.82.1

Author: SummerSmith

azure-stack/user/kubernetes-aks-engine-release-notes.md

@@ -124,7 +124,8 @@ You can find the supported Kubernetes versions for AKS Engine on Azure Stack Hub
 | [v0.79.0](https://github.com/Azure/aks-engine-azurestack/releases/tag/v0.79.0)   | [AKS Base Ubuntu 20.04-LTS Image Distro (2023.296.1)](https://github.com/Azure/aks-engine-azurestack/blob/v0.79.0/vhd/release-notes/aks-engine-ubuntu-2004/aks-engine-azurestack-ubuntu-2004_2023.296.1.txt), [AKS Base Windows Server 2019 Image Containerd (17763.4974.20232961)](https://github.com/Azure/aks-engine-azurestack/blob/v0.79.0/vhd/release-notes/aks-windows-2019-containerd/2019-datacenter-core-azurestack-ctrd-17763.4974.20232961.txt) | 1.26.9**, 1.27.6** | API Model Samples ([Linux](https://github.com/Azure/aks-engine-azurestack/blob/af3e6b25e6304f7c68eb90965b8e9a36887cb457/examples/azure-stack/kubernetes-azurestack.json), [Windows](https://github.com/Azure/aks-engine-azurestack/blob/af3e6b25e6304f7c68eb90965b8e9a36887cb457/examples/azure-stack/kubernetes-windows.json)) |
 | [v0.80.2](https://github.com/Azure/aks-engine-azurestack/releases/tag/v0.80.2)   | [AKS Base Ubuntu 20.04-LTS Image Distro (2024.032.1)](https://github.com/Azure/aks-engine-azurestack/blob/v0.80.2/vhd/release-notes/aks-engine-ubuntu-2004/aks-engine-azurestack-ubuntu-2004_2024.032.1.txt), [AKS Base Windows Server 2019 Image Containerd (17763.5329.20240321)](https://github.com/Azure/aks-engine-azurestack/blob/v0.80.2/vhd/release-notes/aks-windows-2019-containerd/2019-datacenter-core-azurestack-ctrd-17763.5329.20240321.txt) | 1.27.10**, 1.28.6** | API Model Samples ([Linux](https://github.com/Azure/aks-engine-azurestack/blob/96b45e116aef6ae2e5031561b0e10621ae86a068/examples/azure-stack/kubernetes-azurestack.json), [Windows](https://github.com/Azure/aks-engine-azurestack/blob/96b45e116aef6ae2e5031561b0e10621ae86a068/examples/azure-stack/kubernetes-windows.json)) |
 | [v0.80.3](https://github.com/Azure/aks-engine-azurestack/releases/tag/v0.80.3)   | [AKS Base Ubuntu 20.04-LTS Image Distro (2024.032.1)](https://github.com/Azure/aks-engine-azurestack/blob/v0.80.2/vhd/release-notes/aks-engine-ubuntu-2004/aks-engine-azurestack-ubuntu-2004_2024.032.1.txt), [AKS Base Windows Server 2019 Image Containerd (17763.5329.20240321)](https://github.com/Azure/aks-engine-azurestack/blob/v0.80.2/vhd/release-notes/aks-windows-2019-containerd/2019-datacenter-core-azurestack-ctrd-17763.5329.20240321.txt) | 1.27.10**, 1.28.6** | API Model Samples ([Linux](https://github.com/Azure/aks-engine-azurestack/blob/96b45e116aef6ae2e5031561b0e10621ae86a068/examples/azure-stack/kubernetes-azurestack.json), [Windows](https://github.com/Azure/aks-engine-azurestack/blob/96b45e116aef6ae2e5031561b0e10621ae86a068/examples/azure-stack/kubernetes-windows.json)) |
-| [v0.81.1](https://github.com/Azure/aks-engine-azurestack/releases/tag/v0.81.1)   | [AKS Base Ubuntu 20.04-LTS Image Distro (2024.311.1)](https://github.com/Azure/aks-engine-azurestack/blob/master/vhd/release-notes/aks-engine-ubuntu-2004/aks-engine-azurestack-ubuntu-2004_2024.311.1.txt), [AKS Base Windows Server 2019 Image Containerd (17763.6414.20243111)](https://github.com/Azure/aks-engine-azurestack/blob/master/vhd/release-notes/aks-windows-2019-containerd/2019-datacenter-core-azurestack-ctrd-17763.6414.20243111.txt) | 1.28.15**, 1.29.10** | API Model Samples ([Linux](https://github.com/Azure/aks-engine-azurestack/blob/master/examples/azure-stack/kubernetes-azurestack.json), [Windows](https://github.com/Azure/aks-engine-azurestack/blob/master/examples/azure-stack/kubernetes-windows.json)) |
+| [v0.81.1](https://github.com/Azure/aks-engine-azurestack/releases/tag/v0.81.1)   | [AKS Base Ubuntu 20.04-LTS Image Distro (2024.311.1)](https://github.com/Azure/aks-engine-azurestack/blob/master/vhd/release-notes/aks-engine-ubuntu-2004/aks-engine-azurestack-ubuntu-2004_2024.311.1.txt), [AKS Base Windows Server 2019 Image Containerd (17763.6414.20243111)](https://github.com/Azure/aks-engine-azurestack/blob/master/vhd/release-notes/aks-windows-2019-containerd/2019-datacenter-core-azurestack-ctrd-17763.6414.20243111.txt) | 1.28.15**, 1.29.10** | API Model Samples ([Linux](https://github.com/Azure/aks-engine-azurestack/blob/0ea7973bb1826b7607086d4741b73313d72ce256/examples/azure-stack/kubernetes-azurestack.json), [Windows](https://github.com/Azure/aks-engine-azurestack/blob/0ea7973bb1826b7607086d4741b73313d72ce256/examples/azure-stack/kubernetes-windows.json)) |
+| [v0.82.1](https://github.com/Azure/aks-engine-azurestack/releases/tag/v0.82.1)   | [AKS Base Ubuntu 20.04-LTS Image Distro (2025.079.2)](https://github.com/Azure/aks-engine-azurestack/blob/master/vhd/release-notes/aks-engine-ubuntu-2204/aks-engine-azurestack-ubuntu-2204_2025.079.2.txt), [AKS Base Windows Server 2019 Image Containerd (17763.7009.20250792)](https://github.com/Azure/aks-engine-azurestack/blob/master/vhd/release-notes/aks-windows-2019-containerd/2019-datacenter-core-azurestack-ctrd-17763.7009.20250792.txt) | 1.29.15**, 1.30.10** | API Model Samples ([Linux](https://github.com/Azure/aks-engine-azurestack/blob/master/examples/azure-stack/kubernetes-azurestack.json), [Windows](https://github.com/Azure/aks-engine-azurestack/blob/master/examples/azure-stack/kubernetes-windows.json)) |
 
 > [!NOTE]  
 > *Starting from Kubernetes v1.21, only the [Cloud Provider for Azure](https://github.com/Azure/aks-engine-azurestack/blob/master/docs/topics/azure-stack.md#cloud-provider-for-azure) is supported on Azure Stack Hub.
@@ -136,6 +137,10 @@ You can find the supported Kubernetes versions for AKS Engine on Azure Stack Hub
 
 The AKS engine `upgrade` command fully automates the upgrade process of your cluster, and handles virtual machines (VMs), networking, storage, Kubernetes, and orchestration tasks. Before applying the update, make sure to review the release note information.
 
+### Upgrading Kubernetes clusters created with the Ubuntu 20.04 distro
+
+Starting with AKS Engine v0.82.1, the Ubuntu 20.04 distro is not longer a supported option as the OS reached its end-of-life. For AKS Engine v0.82.1 or later versions, aks-engine-azurestack upgrade will automatically overwrite the unsupported `aks-ubuntu-20.04` distro value with `aks-ubuntu-22.04`.
+
 ### What's new with AKSe 0.76.0
 
 - Added support for Kubernetes v1.24.11 and v1.25.7.
@@ -196,6 +201,7 @@ The following list is the complete set of release notes for Azure and Azure Stac
 - https://github.com/Azure/aks-engine-azurestack/releases/tag/v0.80.2
 - https://github.com/Azure/aks-engine-azurestack/releases/tag/v0.80.3
 - https://github.com/Azure/aks-engine-azurestack/releases/tag/v0.81.1
+- https://github.com/Azure/aks-engine-azurestack/releases/tag/v0.82.1
 
 ::: moniker-end