UWP is dead, and a lot of the people who were pushing that weirdly locked in platform have been pushed out of the company.
All future stuff is moving to WinUI 3.x (which belongs to the same family of C# XAML UI libraries, and Visual Studio has a wizard to help you turn your UWP app into a real C# app) and the Microsoft Store is no longer locked to UWP apps only and WinUI 3.x is officially supported on other non-CLR langs (such as calling it from C++ or Rust) and WinUI 3.x is coming to non-Windows platforms (such as Linux).
Microsoft isn't going to transform all their own apps overnight (for simple apps, updating a UWP app to a C# WinUI 3.x app buys you nothing), but will happen over time as WinUI 3.x-only features are added to those apps.
Microsoft set themselves on this path starting uh, like 5 years ago? They publicly announced it about 3 years ago.
Well, it's Microsoft, so every 5 years they release a new API/framework and declare the old one dead/obsolete. But they usually maintain backwards compatibility to their credit, and I almost never credit Microsoft with anything.
whatever was before MFC (I remember using a Charles Petzold book in 1997) --> MFC --> dotNet (many versions) --> XAML/WPF --> UWP
Notice how WinUI 3.x is the first thing named publicly named WinUI, but its already at 3? UWP is 2.x, Metro/WinRT/WPF is 1.x. They're all part of the same family of XAML UIs.
The part that got hard killed, and backwards support was absolutely 100% murdered was the Silverlight stuff, which was a XAML predecessor (and RIA runtime to compete with Flash/Air) written entirely in C#. For performance reasons, the WinRT/WPF->UWP->WinUI 3 branch of the family is largely WinRT-dialect C++.
So no, Microsoft actually hasn't abandoned the tech, they abandoned the dumb idea that all apps need to work on the Windows Phone (which no longer exists) and must be released on the Microsoft Store (which now allows apps in other languages), and everything has to be written in C# (which, again, is no longer forced on programmers), and everything needs to be Windows-only (Project Reunion aka MAUI brings both CLR and non-CLR WinUI apps to Linux).
Also, I'm not sure why you're branching WinUI family off from .net, as WinUI is the UI toolkit for CLR apps.
All future stuff is moving to WinUI 3.x (which belongs to the same family of C# XAML UI libraries, and Visual Studio has a wizard to help you turn your UWP app into a real C# app) and the Microsoft Store is no longer locked to UWP apps only and WinUI 3.x is officially supported on other non-CLR langs (such as calling it from C++ or Rust) and WinUI 3.x is coming to non-Windows platforms (such as Linux).
Microsoft isn't going to transform all their own apps overnight (for simple apps, updating a UWP app to a C# WinUI 3.x app buys you nothing), but will happen over time as WinUI 3.x-only features are added to those apps.
Microsoft set themselves on this path starting uh, like 5 years ago? They publicly announced it about 3 years ago.