Use New Outlook is not present in the registry
Fred Theobald, it doesn't matter. Forget what that Microsoft Engineer said. I don't have it either, though I do have a "Computer\HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\NewOutlook" registry entry. But don't worry about that. Just do what Hal says and install Classic Outlook instead.
Then just make sure you're clicking on the right Outlook icon - for the Classic program, not the New program (which is actually not a newer version of the Classic program, it's a completely different program.)