Hi All.
Since as of this moment, Google search is now placing this topic at the top of it's results page, I felt I must post.
I too have 4 reports of this "optional" PUM regarding MRT.
Registry Value: 4
PUM.Optional.DisableMRT, HKLM\SOFTWARE\POLICIES\MICROSOFT\MRT|DONTOFFERTHROUGHWUAU, No Action By User, [7122], [676880],1.0.10470
PUM.Optional.DisableMRT, HKLM\SOFTWARE\POLICIES\MICROSOFT\MRT|DONTREPORTINFECTIONINFORMATION, No Action By User, [7122], [676881],1.0.10470
PUM.Optional.DisableMRT, HKLM\SOFTWARE\WOW6432NODE\POLICIES\MICROSOFT\MRT|DONTOFFERTHROUGHWUAU, No Action By User, [7122], [676880],1.0.10470
PUM.Optional.DisableMRT, HKLM\SOFTWARE\WOW6432NODE\POLICIES\MICROSOFT\MRT|DONTREPORTINFECTIONINFORMATION, No Action By User, [7122], [676881],1.0.10470
Further research indicate that, at least in my 4 examples, those exact 4 changes do NOT prevent MRT from running/working during Windows updates/other scheduled or forced scans. They simply try to prevent the MRT results from being sent to Microsoft.
If you've ever run DoNotSpy, Windows Anti-Beacon, or any other number of (legitimate non-infected versions) of Windows "privacy" applications, they often make settings changes like the ones being discussed. (I personally choose to opt out of data sharing whenever possible)