The DLP Outlook plugin inserts extra information into the registry

Products

• Data Loss Prevention
• Data Loss Prevention Endpoint Prevent

Issue/Introduction

Why does the DLP Outlook plugin insert so many versions of itself into the registry?

Here's an example of the gpresult report showing the Outlook settings. 
They are all coming from 'Local Group Policy':

Microsoft Outlook 2013/Miscellaneous/List of managed add-ins/Otlk.OutlookAddin.
/Setting/Software\Policies\Microsoft\office\14.0\outlook\resiliency\addinlist\Otlk.OutlookAddin 
/Setting/Software\Policies\Microsoft\office\14\outlook\resiliency\addinlist\Otlk.OutlookAddin 
/Setting/Software\Policies\Microsoft\office\15\outlook\resiliency\addinlist\Otlk.OutlookAddin  
/Setting/Software\Policies\Microsoft\office\16\outlook\resiliency\addinlist\Otlk.OutlookAddin  

Resolution

The Outlook plugin lays down the various registry entries because it does not determine what version of Outlook is on the endpoint, so it lays down one registry entry for each version of Outlook we support.

While it would not break anything to manually remove the unused Outlook plugin versions from the registry, it would be an exercise in futility.
Every time the Outlook plugin is loaded, it will re-write the missing registry keys.