The Ethereum Foundation has put Pascal Caversaccio, a co-founder of a security response group called SEAL 911, on its four-person board, alongside Buterin and two others, as it calls privacy and security "non-negotiable protocol guarantees." A board is a form of trusted third party by design; it governs the governors. Adding a security specialist to it is a sound incentive if the goal is catching failures before they happen. Whether a protocol can guarantee privacy while being overseen by four named people is a separate question, and probably the harder one.