Forum Discussion
Use modern UI （Fluent）to rebuild the most commonly used system components (such as file explorer).
Regarding the points I mentioned, the feedback center has the highest votes all year round. I have sent these feedbacks in the feedback center. Many of them have been incorporated into "collections" because more than one person mentioned these suggestions.
For the resource manager, FDS (or UWP) is used, but in fact, everyone only cares about the appearance, as long as the appearance is changed. After all, explorer.exe is a desktop environment. I am not sure whether this thing can be UWP, or divide the desktop environment and file browsing. Separation is also a solution) The suggestion is 6186 votes, 280+ comments; the suggestion that the control panel is to complete the migration of the settings app as soon as possible is 9000+ votes; the file explorer is added to the tab page function 25000+ votes (I think "Restore" is more appropriate, after all, Microsoft has tested the global-tabs that are not restricted by a single app); but it has no effect
Generally speaking, Microsoft will end the feature development in March, complete the RTM version in June, and push the official version in September. It is now less than a month before the deadline of 21H2（Sun Valley）, and I think it is difficult for us to see real changes.
https://www.windowscentral.com/windows-10-sun-valley-features-everything-we-know
Probably the biggest change is the "alarm and clock"
- alarm and clock is just the beginning, i got the update more than 2 weeks ago, those dates are all up in the air, nothing concrete to rely on