This is unfortunately beyond my understanding of the intricacies of the protocol. My guess is that pool centralization is still required because you still need a pool. How much control does that pool have? Certainly less than before. But more than an infrastructure that doesn't need pools at all (for example, a truly P2P "pool").

As long as you need a pool for something, there is some centralization and risk of the pool being attacked for some nefarious purpose. But hopefully someone here can chime in with a source or explanation which is more well-explained.