The UserInformation class does not exist anymore in Windows 10.
See this link:
https://msdn.microsoft.com/library/windows/apps/windows.system.userprofile.userinformation.aspx
If you scroll down to remark you'll find that the UserInformation class is replaced by the User Class:
Windows 10:
Apps compiled for Windows 8 that use the UserInformation class no
longer return user information when running on Windows 10. This is
because in Windows 10, apps do not have access to user information
without explicit user consent, unlike in Windows 8 where this
permission is granted by default.
If you have a Windows 8 app that uses the UserInformation class, you
should migrate your app to the Universal Windows Platform (UWP) and
access the User class instead. Universal Windows Platform (UWP) apps
that access user information are now expected to declare a new
capability, uap:userAccountInformation, and call new APIs,
Windows.System.User.FindAllAsync and User.GetPropertiesAsync, to get
the data.
Users installing the app are prompted to allow access to their user
information. If the user allows the app to access the information, the
app appears listed in the Privacy page of the Windows 10 Settings UI
(Settings > Privacy > Account info). This allows Windows 10 users to
enable access to user information on a per-app basis.
so the short answer is NO it's not possible without changing your code.
What you could do is check the OS runtime and implement 2 ways of getting the user info. 1 for windows 8 and 1 for windows 1 (by doing this you also enable your app to be used on Windows 10 devices)
How can I detect if my app is running on Windows 10
If app is running Windows 10: use User class
Else: use UserInformation class.
To test how it works on Windows 8 on your Windows 10 device you could add a Windows 8 VM and test the app in there. (not perfect but at least it is something)