Just updated to v2.3.7.0 and i removed Cortana in a test Iso. Problem here is, that the Cortana button in the Taskbar still shows, which in my opinion shouldnt be the case if Cortana is removed.
Code:
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced]
"ShowCortanaButton"=dword:00000000