> Organisationally it never works to have a group whose only job is to say no to some other group.

That is only true where the pressure to be [the thing that is inconvenient to the other group] is not from a source that can cause massive problems if non-compliance is spotted. When the blocking group is legally mandated or otherwise really has teeth or is defending the company against an external regulator with teeth, then it works better (though obviously not perfectly). Think legal and compliance in banking realms, where the company significantly fined and the people breaking the rules could be sacked & blackballed (though sometimes not the people ordering them to break the rules!) when something bad is noticed. That is quite different to an ethics officer in a company like OpenAI where the position is basically there for PR purposes (“look plebs, we care about doing the right thing, honest, we got a manager with a small team dedicated to it” and “look [government body], we are regulating ourselves, do you really need to spend time looking too?”) and therefore has no real teeth directly or indirectly especially as fault for non-compliance might not be easy to attribute.