Tomando sua abordagem literal, você obterá o último elemento separado .
do nome, mas haverá muitas entradas 0,1,2,3,4,6,00,xaml
dos aplicativos com informações de versão anexadas e tipo xaml:
Get-AppxPackage -AllUsers | Select -Expand Name|%{"{0,-40} {1}" -f $_.split(".")[-1],$_}
Exemplo de saída:
BrokerPlugin Microsoft.AAD.BrokerPlugin
BioEnrollment Microsoft.BioEnrollment
LockApp Microsoft.LockApp
MicrosoftEdge Microsoft.MicrosoftEdge
PPIProjection Microsoft.PPIProjection
ChxApp Microsoft.Windows.Apprep.ChxApp
AssignedAccessLockApp Microsoft.Windows.AssignedAccessLockApp
CloudExperienceHost Microsoft.Windows.CloudExperienceHost
ContentDeliveryManager Microsoft.Windows.ContentDeliveryManager
Cortana Microsoft.Windows.Cortana
ParentalControls Microsoft.Windows.ParentalControls
SecondaryTileExperience Microsoft.Windows.SecondaryTileExperience
SecureAssessmentBrowser Microsoft.Windows.SecureAssessmentBrowser
XboxGameCallableUI Microsoft.XboxGameCallableUI
ContactSupport Windows.ContactSupport
immersivecontrolpanel windows.immersivecontrolpanel
MiracastView Windows.MiracastView
PrintDialog Windows.PrintDialog
3 Microsoft.NET.Native.Runtime.1.3
3 Microsoft.NET.Native.Runtime.1.3
3 Microsoft.NET.Native.Framework.1.3
3 Microsoft.NET.Native.Framework.1.3