So we currently populate this flag for HKLM, but we cannot populate HKCU at this time. In order to set that flag for HKCU, you'll likely need to use a GPO or some other method to set: HKCU:\SOFTWARE\Zoom\OutlookPlugin\autoUpdate:dword:0
I assume if it is set at the HKLM level, that setting will actually be set for new users, but not for existing users.