Hi Igor

Here is the result for one affected file:

C:\Program Files\WindowsApps\Microsoft.Windows.Photos_15.1001.16470.0_neutral_split.scale-100_8wekyb3d8bbwe>\users\gary\downloads\getfileattr appxblockmap.xml
GFA attributes: 00000020
FFF attributs: 00000020
OS Ver: 10.0.15063

No, they are not all in Program Files\WindowsApps. For example, there are many files in:
c:\windows\assembly\nativeimages…
c:\windows\WinSxS.…
c:\windows\system32
c:\windows\syswow64

Gary