I don't buy the fact that "Ferderated Learning" is privacy centric so much as it is liability and/or privacy-marketing centric. I feel that in the long run we will discover that using "ML" as a black box to smuggle user data off device won't hold up to scrutiny.
I find that hard to believe as Google’s definition of privacy is not mine. I believe Google could be awesome if they wanted, but it’s in conflict with their business mode.