That's pretty much what I've been trying to say - I couldn't find the Powershell script I had before, but I dis find this on MSDN. It might describe the timedate stamp a little better than I did. This goes back to Win8 and is specific to customizing Start with XML.
Still it might make things more clear. The key is the lastwritetime and the PowerShell updates that with the current time.
To use the script, you'lll have to change it to accept a parameter or modify it with the real name of the shortcut (.lnk)
SourceStep 7. Refresh your shortcut file
If your app is already installed, you must nudge your shortcut after the new or updated .VisualElementsManifest.xml is in place or it will be ignored.
The following Windows PowerShell command example for the fictional Contoso app is one model for how to accomplish this, although there are many ways that it can be done.
Code:(ls "$env:programdata\microsoft\windows\start menu\programs\contoso.lnk").lastwritetime = get-date
That's all I have - good luck.