No doubt that it's easy to mess up Group Policies. He's not wrong in that you have to very clearly read each one's description because different policies expect you to do different things sometimes to do the same things. That's definitely not new to Windows 10, and arguably just bad design on Microsoft's part; there appears to be no standardized design pattern to how GPOs should function across the whole Windows team.
But it is still entirely possible to disable all telemetry with it.
But it is still entirely possible to disable all telemetry with it.