Microsoft"s Insider builds often tend to reveal interesting features that are hidden from plain sight as they are not a part of the announced set of features, changes, and improvements in release notes. The latest Canary build 25987 is the same as Windows enthusiast and Twitter (now X) user Xeno noticed some new DLL and EXE files in the System32 folder.
New files in system32!
— Xeno (@XenoPanther) November 1, 2023
controlcenter.dll
mlenginestub.exe (Undocked MLEngine Stub)
shellhost.exe (ShellHost)
sortwindows64.dll (SortWindows64 dll)
Out of the four new files, we do get an idea about what the ControlCenter DLL or the ShellHost EXE files may be. If you guessed they had to do something with the Windows 11 Shell, you would be right. Twitter (X) user Albacore, who is also another Windows enthusiast and a developer, noted that these new files potentially indicate what Microsoft"s plans are with UWP (Universal Windows Platform) as Albacore suggests UWP could be going away.
This follows an August finding where some Windows 10 elements from Explorer EXE were removed from 11.
I think it"s finally fair to say that UWP is dying ⚰️
— Albacore (@thebookisclosed) November 2, 2023
Windows 11 Canary Build 25987 starts the migration of XAML shell experiences from UWP to Win32+XAML Hosting. Control Center is the first to ship. To use the new variant enable 45046901 (CCW), 44685875 (ShellUIHostCoordinator) pic.twitter.com/0cCpjquZV4
Albacore adds further context about the new ControlCenter and ShellHost files in their Twitter thread:
In the screenshot you can see the new ShellHost and the ControlCenter.dll it hosts, directly in System32. No more SystemApps, no MSIX packaging, no UWP. ShellExperienceHost doesn"t run on boot at all with these features enabled
— Albacore (@thebookisclosed) November 2, 2023
Notification center still uses it (starts on demand)
As for why Microsoft may be looking to make such a move, it is hard to know. Earlier this year, the company did have a bit of trouble fixing UWP app bugs, though they were eventually resolved. More recently in July, Arm32 UWP support was ended.