Yes, One way is to use the following settings in your O365 GPO: 

Yes it is. One way is to enumerate the Registry-keys that is used for Sharepoint for the user and set them to NotConnected and NoCapabilities. This VBScript does the trix. 'On Error Resume Next '========================================================= 'Remove any SHAREPOINT "Save As" Default Options in Office 'If it works, created by: 'Created by Tom Jorgensen 'If it do not work, I donno who wrote this '18:23 09.11.2016 '========================================================= Const HKEY_CURRENT_USER = &H80000001 strKeyPath = "Software\Microsoft\Office\16.0\Common\ServicesManagerCache\Identities" Set objShell = CreateObject("WScript.Shell") Set reg = GetObject("winmgmts://./root/default:StdRegProv") EnumerateKeys HKEY_CURRENT_USER, strKeyPath Sub EnumerateKeys(hive, key)   reg.EnumKey hive, key, arrSubKeys   If Not IsNull(arrSubKeys) Then     For Each subkey In arrSubKeys       If InStr(s...