Microsoft wants to further shift its attention towards Windows 10. To do so, it has announced that no new apps will be distributed through the Windows 8 App Store from Oct. 31st. This applies to Windows Phone 8 apps as well.
A deadline has been set for app updates as well. According to it, after July 2019, there will be no app updates for Windows Phone 8.x and for Windows 8/8.1 devices the deadline is July 1, 2023.
This decision is not likely to affect a large number of developers as most of them are already developing apps for Windows 10 and a very less percentage of developers are interested in submitting apps for Windows 8 and Windows Phone 8.
Microsoft has encouraged developers to find a means to port their existing app to the Universal Windows Platform (UWP) which allows the developers to create a single Windows 10 app package.
This announcement was imminent as the Windows 8 app store has failed to garner the attention of developers and users.