WinUI is the native UI platform for Windows 10 and is currently under active development by the Windows developer platform team. The library provides a number of benefits which makes it the best way to create user interfaces for Windows apps.
Yesterday Microsoft published the release roadmap of WinUI 3.0, which includes the features that coming up next, and the expected availability date. Here's the list published by the company though they didn't guarantee any changes to it in the future.