As much as I generally distrust google with privacy when it comes to actually handing over data, in this case it's an open protocol that has just been drafted by google; anyone can run a server or make their own implementation. It also never touches private keys, only public. If you want a public key to have limited distribution, you don't put it on a keyserver, and instead only exchange it with the people you would like to in person or over some other verified and secure channel.
It does have a somewhat anti-privacy feature in that if I understand it correctly, it keeps a record of messages between participants (in the sense of a record existing that a message was exchanged although not the content), but that level of data is already accessible to NSA/GCHQ anyway.
It does have a somewhat anti-privacy feature in that if I understand it correctly, it keeps a record of messages between participants (in the sense of a record existing that a message was exchanged although not the content), but that level of data is already accessible to NSA/GCHQ anyway.