Finally results, which might be useful to someone else.
Below are some registry keys/values obtained from autodesk support. Note my PC had all values the same EXCEPT ONE. Changing this one value caused Cad Manager Tool to run.
Then, when it ran, it fixed the New AcadApplicationClass instantiation problem.
Below is the fix:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Autodesk\AutoCAD\R16.1\ACAD-301:409\CadManagerControl]
@=""
"CurVer"="1.0"
[HKEY_LOCAL_MACHINE\SOFTWARE\Autodesk\AutoCAD\R16.1\ACAD-301:409\CadManagerControl\CommunicationCenter]
@=""
"LocalPatchListLocation"=""
"EnableSerialNumberPassing"=dword:00000000
"EnableNonPatchNotifications"=dword:00000001
"EnableCommunicationCenter"=dword:00000001
"DataPollingURL"="http://webservices.autodesk.com/CommCntrLinkCollectionRequest"
"PreviewMode"=dword:00000000
"MaintenancePatchNotificationOption"=dword:00000001
[HKEY_LOCAL_MACHINE\SOFTWARE\Autodesk\AutoCAD\R16.1\ACAD-301:409\CadManagerControl\DesignCenter]
"HomePageUrl"="http://webservices.autodesk.com/DesignCenter"
"EnableDesignCenter"=dword:00000001
"EnableSerialNumberPassing"=dword:00000000
@=""