As a part of our Windows device life cycle, Microsoft Store will soon stop accepting new apps with Windows Phone 8.x or earlier or Windows 8/8.1 packages (XAP and APPX). Soon after that date, we will stop distributing app updates to Windows Phone 8.x or earlier and Windows 8/8.1 devices; at that time, updates will only be made available to customers using Windows 10 devices.
Take note of the following dates so you can effectively plan your development cycles:
- October 31st, 2018 – Microsoft will stop accepting new app submissions with Windows Phone 8.x or earlier or Windows 8/8.1 packages (XAP or APPX).
- This will not affect existing apps with packages targeting Windows Phone 8.x or earlier and/or Windows 8/8.1. You can continue to submit updates to these apps as described below.
- July 1st, 2019 – Microsoft will stop distributing app updates to Windows Phone 8.x or earlier devices, and Windows 8.
- You’ll still be able to publish updates to all apps (including those with Windows Phone 8.x or earlier packages, and Windows 8 packages). However, these updates will only be made available to Windows 10 devices.
We encourage you to explore how you can port your existing app to the Universal Windows Platform (UWP) where you can create a single Windows 10 app package that your customers can install onto all device families. You can learn more about UWP apps here.
- July 1st, 2023 – Microsoft will stop distributing app updates to Windows 8.1 devices.
- You’ll still be able to publish updates to all apps (including those with Windows 8.1 packages). However, these updates will only be made available to Windows 10 devices.
Source: https://blogs.windows.com/buildinga...-8-8-1-packages-submitted-to-microsoft-store/